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path: root/drivers/usb/core/hub.c
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2024-05-17usb: Fix regression caused by invalid ep0 maxpacket in virtual SuperSpeed deviceAlan Stern1-2/+3
commit c78c3644b772e356ca452ae733a3c4de0fb11dc8 upstream. A virtual SuperSpeed device in the FreeBSD BVCP package (https://bhyve.npulse.net/) presents an invalid ep0 maxpacket size of 256. It stopped working with Linux following a recent commit because now we check these sizes more carefully than before. Fix this regression by using the bMaxpacketSize0 value in the device descriptor for SuperSpeed or faster devices, even if it is invalid. This is a very simple-minded change; we might want to check more carefully for values that actually make some sense (for instance, no smaller than 64). Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-and-tested-by: Roger Whittaker <roger.whittaker@suse.com> Closes: https://bugzilla.suse.com/show_bug.cgi?id=1220569 Link: https://lore.kernel.org/linux-usb/9efbd569-7059-4575-983f-0ea30df41871@suse.com/ Fixes: 59cf44575456 ("USB: core: Fix oversight in SuperSpeed initialization") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/4058ac05-237c-4db4-9ecc-5af42bdb4501@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-13USB: core: Add hub_get() and hub_put() routinesAlan Stern1-7/+16
commit ee113b860aa169e9a4d2c167c95d0f1961c6e1b8 upstream. Create hub_get() and hub_put() routines to encapsulate the kref_get() and kref_put() calls in hub.c. The new routines will be used by the next patch in this series. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Link: https://lore.kernel.org/r/604da420-ae8a-4a9e-91a4-2d511ff404fb@rowland.harvard.edu Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-23USB: hub: check for alternate port before enabling A_ALT_HNP_SUPPORTOliver Neukum1-11/+19
commit f17c34ffc792bbb520e4b61baa16b6cfc7d44b13 upstream. The OTG 1.3 spec has the feature A_ALT_HNP_SUPPORT, which tells a device that it is connected to the wrong port. Some devices refuse to operate if you enable that feature, because it indicates to them that they ought to request to be connected to another port. According to the spec this feature may be used based only the following three conditions: 6.5.3 a_alt_hnp_support Setting this feature indicates to the B-device that it is connected to an A-device port that is not capable of HNP, but that the A-device does have an alternate port that is capable of HNP. The A-device is required to set this feature under the following conditions: • the A-device has multiple receptacles • the A-device port that connects to the B-device does not support HNP • the A-device has another port that does support HNP A check for the third and first condition is missing. Add it. Signed-off-by: Oliver Neukum <oneukum@suse.com> Cc: stable <stable@kernel.org> Fixes: 7d2d641c44269 ("usb: otg: don't set a_alt_hnp_support feature for OTG 2.0 device") Link: https://lore.kernel.org/r/20240122153545.12284-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-23usb: hub: Replace hardcoded quirk value with BIT() macroHardik Gajjar1-2/+2
[ Upstream commit 6666ea93d2c422ebeb8039d11e642552da682070 ] This patch replaces the hardcoded quirk value in the macro with BIT(). Signed-off-by: Hardik Gajjar <hgajjar@de.adit-jv.com> Reviewed-by: Alan Stern <stern@rowland.harvard.edu> Link: https://lore.kernel.org/r/20231205181829.127353-1-hgajjar@de.adit-jv.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-12-08driver core: Move the "removable" attribute from USB to coreRajat Jain1-6/+7
[ Upstream commit 70f400d4d957c2453c8689552ff212bc59f88938 ] Move the "removable" attribute from USB to core in order to allow it to be supported by other subsystem / buses. Individual buses that want to support this attribute can populate the removable property of the device while enumerating it with the 3 possible values - - "unknown" - "fixed" - "removable" Leaving the field unchanged (i.e. "not supported") would mean that the attribute would not show up in sysfs for that device. The UAPI (location, symantics etc) for the attribute remains unchanged. Move the "removable" attribute from USB to the device core so it can be used by other subsystems / buses. By default, devices do not have a "removable" attribute in sysfs. If a subsystem or bus driver wants to support a "removable" attribute, it should call device_set_removable() before calling device_register() or device_add(), e.g.: device_set_removable(dev, DEVICE_REMOVABLE); device_register(dev); The possible values and the resulting sysfs attribute contents are: DEVICE_REMOVABLE_UNKNOWN -> "unknown" DEVICE_REMOVABLE -> "removable" DEVICE_FIXED -> "fixed" Convert the USB "removable" attribute to use this new device core functionality. There should be no user-visible change in the location or semantics of attribute for USB devices. Reviewed-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Rajat Jain <rajatja@google.com> Link: https://lore.kernel.org/r/20210524171812.18095-1-rajatja@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Stable-dep-of: 432e664e7c98 ("drm/amdgpu: don't use ATRM for external devices") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-10-25usb: core: Track SuperSpeed Plus GenXxYThinh Nguyen1-0/+78
[ Upstream commit 0299809be415567366b66f248eed93848b8dc9f3 ] Introduce ssp_rate field to usb_device structure to capture the connected SuperSpeed Plus signaling rate generation and lane count with the corresponding usb_ssp_rate enum. Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com> Link: https://lore.kernel.org/r/b7805d121e5ae4ad5ae144bd860b6ac04ee47436.1615432770.git.Thinh.Nguyen@synopsys.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Stable-dep-of: f74a7afc224a ("usb: hub: Guard against accesses to uninitialized BOS descriptors") Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-10-25usb: hub: Guard against accesses to uninitialized BOS descriptorsRicardo Cañuelo1-4/+24
commit f74a7afc224acd5e922c7a2e52244d891bbe44ee upstream. Many functions in drivers/usb/core/hub.c and drivers/usb/core/hub.h access fields inside udev->bos without checking if it was allocated and initialized. If usb_get_bos_descriptor() fails for whatever reason, udev->bos will be NULL and those accesses will result in a crash: BUG: kernel NULL pointer dereference, address: 0000000000000018 PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 5 PID: 17818 Comm: kworker/5:1 Tainted: G W 5.15.108-18910-gab0e1cb584e1 #1 <HASH:1f9e 1> Hardware name: Google Kindred/Kindred, BIOS Google_Kindred.12672.413.0 02/03/2021 Workqueue: usb_hub_wq hub_event RIP: 0010:hub_port_reset+0x193/0x788 Code: 89 f7 e8 20 f7 15 00 48 8b 43 08 80 b8 96 03 00 00 03 75 36 0f b7 88 92 03 00 00 81 f9 10 03 00 00 72 27 48 8b 80 a8 03 00 00 <48> 83 78 18 00 74 19 48 89 df 48 8b 75 b0 ba 02 00 00 00 4c 89 e9 RSP: 0018:ffffab740c53fcf8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffffa1bc5f678000 RCX: 0000000000000310 RDX: fffffffffffffdff RSI: 0000000000000286 RDI: ffffa1be9655b840 RBP: ffffab740c53fd70 R08: 00001b7d5edaa20c R09: ffffffffb005e060 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 R13: ffffab740c53fd3e R14: 0000000000000032 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffffa1be96540000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000018 CR3: 000000022e80c005 CR4: 00000000003706e0 Call Trace: hub_event+0x73f/0x156e ? hub_activate+0x5b7/0x68f process_one_work+0x1a2/0x487 worker_thread+0x11a/0x288 kthread+0x13a/0x152 ? process_one_work+0x487/0x487 ? kthread_associate_blkcg+0x70/0x70 ret_from_fork+0x1f/0x30 Fall back to a default behavior if the BOS descriptor isn't accessible and skip all the functionalities that depend on it: LPM support checks, Super Speed capabilitiy checks, U1/U2 states setup. Signed-off-by: Ricardo Cañuelo <ricardo.canuelo@collabora.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20230830100418.1952143-1-ricardo.canuelo@collabora.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-09-19USB: core: Fix oversight in SuperSpeed initializationAlan Stern1-12/+24
commit 59cf445754566984fd55af19ba7146c76e6627bc upstream. Commit 85d07c556216 ("USB: core: Unite old scheme and new scheme descriptor reads") altered the way USB devices are enumerated following detection, and in the process it messed up the initialization of SuperSpeed (or faster) devices: [ 31.650759] usb 2-1: new SuperSpeed Plus Gen 2x1 USB device number 2 using xhci_hcd [ 31.663107] usb 2-1: device descriptor read/8, error -71 [ 31.952697] usb 2-1: new SuperSpeed Plus Gen 2x1 USB device number 3 using xhci_hcd [ 31.965122] usb 2-1: device descriptor read/8, error -71 [ 32.080991] usb usb2-port1: attempt power cycle ... The problem was caused by the commit forgetting that in SuperSpeed or faster devices, the device descriptor uses a logarithmic encoding of the bMaxPacketSize0 value. (For some reason I thought the 255 case in the switch statement was meant for these devices, but it isn't -- it was meant for Wireless USB and is no longer needed.) We can fix the oversight by testing for buf->bMaxPacketSize0 = 9 (meaning 512, the actual maxpacket size for ep0 on all SuperSpeed devices) and straightening out the logic that checks and adjusts our initial guesses of the maxpacket value. Reported-and-tested-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com> Closes: https://lore.kernel.org/linux-usb/20230810002257.nadxmfmrobkaxgnz@synopsys.com/ Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Fixes: 85d07c556216 ("USB: core: Unite old scheme and new scheme descriptor reads") Link: https://lore.kernel.org/r/8809e6c5-59d5-4d2d-ac8f-6d106658ad73@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-09-19USB: core: Fix race by not overwriting udev->descriptor in hub_port_init()Alan Stern1-44/+70
commit ff33299ec8bb80cdcc073ad9c506bd79bb2ed20b upstream. Syzbot reported an out-of-bounds read in sysfs.c:read_descriptors(): BUG: KASAN: slab-out-of-bounds in read_descriptors+0x263/0x280 drivers/usb/core/sysfs.c:883 Read of size 8 at addr ffff88801e78b8c8 by task udevd/5011 CPU: 0 PID: 5011 Comm: udevd Not tainted 6.4.0-rc6-syzkaller-00195-g40f71e7cd3c6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 print_address_description.constprop.0+0x2c/0x3c0 mm/kasan/report.c:351 print_report mm/kasan/report.c:462 [inline] kasan_report+0x11c/0x130 mm/kasan/report.c:572 read_descriptors+0x263/0x280 drivers/usb/core/sysfs.c:883 ... Allocated by task 758: ... __do_kmalloc_node mm/slab_common.c:966 [inline] __kmalloc+0x5e/0x190 mm/slab_common.c:979 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:680 [inline] usb_get_configuration+0x1f7/0x5170 drivers/usb/core/config.c:887 usb_enumerate_device drivers/usb/core/hub.c:2407 [inline] usb_new_device+0x12b0/0x19d0 drivers/usb/core/hub.c:2545 As analyzed by Khazhy Kumykov, the cause of this bug is a race between read_descriptors() and hub_port_init(): The first routine uses a field in udev->descriptor, not expecting it to change, while the second overwrites it. Prior to commit 45bf39f8df7f ("USB: core: Don't hold device lock while reading the "descriptors" sysfs file") this race couldn't occur, because the routines were mutually exclusive thanks to the device locking. Removing that locking from read_descriptors() exposed it to the race. The best way to fix the bug is to keep hub_port_init() from changing udev->descriptor once udev has been initialized and registered. Drivers expect the descriptors stored in the kernel to be immutable; we should not undermine this expectation. In fact, this change should have been made long ago. So now hub_port_init() will take an additional argument, specifying a buffer in which to store the device descriptor it reads. (If udev has not yet been initialized, the buffer pointer will be NULL and then hub_port_init() will store the device descriptor in udev as before.) This eliminates the data race responsible for the out-of-bounds read. The changes to hub_port_init() appear more extensive than they really are, because of indentation changes resulting from an attempt to avoid writing to other parts of the usb_device structure after it has been initialized. Similar changes should be made to the code that reads the BOS descriptor, but that can be handled in a separate patch later on. This patch is sufficient to fix the bug found by syzbot. Reported-and-tested-by: syzbot+18996170f8096c6174d0@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-usb/000000000000c0ffe505fe86c9ca@google.com/#r Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Cc: Khazhy Kumykov <khazhy@google.com> Fixes: 45bf39f8df7f ("USB: core: Don't hold device lock while reading the "descriptors" sysfs file") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/b958b47a-9a46-4c22-a9f9-e42e42c31251@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-09-19USB: core: Change usb_get_device_descriptor() APIAlan Stern1-21/+23
commit de28e469da75359a2bb8cd8778b78aa64b1be1f4 upstream. The usb_get_device_descriptor() routine reads the device descriptor from the udev device and stores it directly in udev->descriptor. This interface is error prone, because the USB subsystem expects in-memory copies of a device's descriptors to be immutable once the device has been initialized. The interface is changed so that the device descriptor is left in a kmalloc-ed buffer, not copied into the usb_device structure. A pointer to the buffer is returned to the caller, who is then responsible for kfree-ing it. The corresponding changes needed in the various callers are fairly small. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Link: https://lore.kernel.org/r/d0111bb6-56c1-4f90-adf2-6cfe152f6561@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-09-19USB: core: Unite old scheme and new scheme descriptor readsAlan Stern1-79/+94
commit 85d07c55621676d47d873d2749b88f783cd4d5a1 upstream. In preparation for reworking the usb_get_device_descriptor() routine, it is desirable to unite the two different code paths responsible for initially determining endpoint 0's maximum packet size in a newly discovered USB device. Making this determination presents a chicken-and-egg sort of problem, in that the only way to learn the maxpacket value is to get it from the device descriptor retrieved from the device, but communicating with the device to retrieve a descriptor requires us to know beforehand the ep0 maxpacket size. In practice this problem is solved in two different ways, referred to in hub.c as the "old scheme" and the "new scheme". The old scheme (which is the approach recommended by the USB-2 spec) involves asking the device to send just the first eight bytes of its device descriptor. Such a transfer uses packets containing no more than eight bytes each, and every USB device must have an ep0 maxpacket size >= 8, so this should succeed. Since the bMaxPacketSize0 field of the device descriptor lies within the first eight bytes, this is all we need. The new scheme is an imitation of the technique used in an early Windows USB implementation, giving it the happy advantage of working with a wide variety of devices (some of them at the time would not work with the old scheme, although that's probably less true now). It involves making an initial guess of the ep0 maxpacket size, asking the device to send up to 64 bytes worth of its device descriptor (which is only 18 bytes long), and then resetting the device to clear any error condition that might have resulted from the guess being wrong. The initial guess is determined by the connection speed; it should be correct in all cases other than full speed, for which the allowed values are 8, 16, 32, and 64 (in this case the initial guess is 64). The reason for this patch is that the old- and new-scheme parts of hub_port_init() use different code paths, one involving usb_get_device_descriptor() and one not, for their initial reads of the device descriptor. Since these reads have essentially the same purpose and are made under essentially the same circumstances, this is illogical. It makes more sense to have both of them use a common subroutine. This subroutine does basically what the new scheme's code did, because that approach is more general than the one used by the old scheme. It only needs to know how many bytes to transfer and whether or not it is being called for the first iteration of a retry loop (in case of certain time-out errors). There are two main differences from the former code: We initialize the bDescriptorType field of the transfer buffer to 0 before performing the transfer, to avoid possibly accessing an uninitialized value afterward. We read the device descriptor into a temporary buffer rather than storing it directly into udev->descriptor, which the old scheme implementation used to do. Since the whole point of this first read of the device descriptor is to determine the bMaxPacketSize0 value, that is what the new routine returns (or an error code). The value is stored in a local variable rather than in udev->descriptor. As a side effect, this necessitates moving a section of code that checks the bcdUSB field for SuperSpeed devices until after the full device descriptor has been retrieved. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Cc: Oliver Neukum <oneukum@suse.com> Link: https://lore.kernel.org/r/495cb5d4-f956-4f4a-a875-1e67e9489510@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-03USB: core: Don't hold device lock while reading the "descriptors" sysfs fileAlan Stern1-3/+2
commit 45bf39f8df7f05efb83b302c65ae3b9bc92b7065 upstream. Ever since commit 83e83ecb79a8 ("usb: core: get config and string descriptors for unauthorized devices") was merged in 2013, there has been no mechanism for reallocating the rawdescriptors buffers in struct usb_device after the initial enumeration. Before that commit, the buffers would be deallocated when a device was deauthorized and reallocated when it was authorized and enumerated. This means that the locking in the read_descriptors() routine is not needed, since the buffers it reads will never be reallocated while the routine is running. This locking can interfere with user programs trying to read a hub's descriptors via sysfs while new child devices of the hub are being initialized, since the hub is locked during this procedure. Since the locking in read_descriptors() hasn't been needed for over nine years, we can remove it. Reported-and-tested-by: Troels Liebe Bentsen <troels@connectedcars.dk> Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: stable@vger.kernel.org Link: https://lore.kernel.org/r/Y9l+wDTRbuZABzsE@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-24usb: core: hub: disable autosuspend for TI TUSB8041Flavio Suligoi1-0/+13
commit 7171b0e261b17de96490adf053b8bb4b00061bcf upstream. The Texas Instruments TUSB8041 has an autosuspend problem at high temperature. If there is not USB traffic, after a couple of ms, the device enters in autosuspend mode. In this condition the external clock stops working, to save energy. When the USB activity turns on, ther hub exits the autosuspend state, the clock starts running again and all works fine. At ambient temperature all works correctly, but at high temperature, when the USB activity turns on, the external clock doesn't restart and the hub disappears from the USB bus. Disabling the autosuspend mode for this hub solves the issue. Signed-off-by: Flavio Suligoi <f.suligoi@asem.it> Cc: stable <stable@kernel.org> Acked-by: Alan Stern <stern@rowland.harvard.edu> Link: https://lore.kernel.org/r/20221219124759.3207032-1-f.suligoi@asem.it Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-28USB: core: Fix RST error in hub.cAlan Stern1-1/+1
commit 766a96dc558385be735a370db867e302c8f22153 upstream. A recent commit added an invalid RST expression to a kerneldoc comment in hub.c. The fix is trivial. Fixes: 9c6d778800b9 ("USB: core: Prevent nested device-reset calls") Cc: <stable@vger.kernel.org> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com> Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Link: https://lore.kernel.org/r/YxDDcsLtRZ7c20pq@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-08USB: core: Prevent nested device-reset callsAlan Stern1-0/+10
commit 9c6d778800b921bde3bff3cff5003d1650f942d1 upstream. Automatic kernel fuzzing revealed a recursive locking violation in usb-storage: ============================================ WARNING: possible recursive locking detected 5.18.0 #3 Not tainted -------------------------------------------- kworker/1:3/1205 is trying to acquire lock: ffff888018638db8 (&us_interface_key[i]){+.+.}-{3:3}, at: usb_stor_pre_reset+0x35/0x40 drivers/usb/storage/usb.c:230 but task is already holding lock: ffff888018638db8 (&us_interface_key[i]){+.+.}-{3:3}, at: usb_stor_pre_reset+0x35/0x40 drivers/usb/storage/usb.c:230 ... stack backtrace: CPU: 1 PID: 1205 Comm: kworker/1:3 Not tainted 5.18.0 #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Workqueue: usb_hub_wq hub_event Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2988 [inline] check_deadlock kernel/locking/lockdep.c:3031 [inline] validate_chain kernel/locking/lockdep.c:3816 [inline] __lock_acquire.cold+0x152/0x3ca kernel/locking/lockdep.c:5053 lock_acquire kernel/locking/lockdep.c:5665 [inline] lock_acquire+0x1ab/0x520 kernel/locking/lockdep.c:5630 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x14f/0x1610 kernel/locking/mutex.c:747 usb_stor_pre_reset+0x35/0x40 drivers/usb/storage/usb.c:230 usb_reset_device+0x37d/0x9a0 drivers/usb/core/hub.c:6109 r871xu_dev_remove+0x21a/0x270 drivers/staging/rtl8712/usb_intf.c:622 usb_unbind_interface+0x1bd/0x890 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:545 [inline] device_remove+0x11f/0x170 drivers/base/dd.c:537 __device_release_driver drivers/base/dd.c:1222 [inline] device_release_driver_internal+0x1a7/0x2f0 drivers/base/dd.c:1248 usb_driver_release_interface+0x102/0x180 drivers/usb/core/driver.c:627 usb_forced_unbind_intf+0x4d/0xa0 drivers/usb/core/driver.c:1118 usb_reset_device+0x39b/0x9a0 drivers/usb/core/hub.c:6114 This turned out not to be an error in usb-storage but rather a nested device reset attempt. That is, as the rtl8712 driver was being unbound from a composite device in preparation for an unrelated USB reset (that driver does not have pre_reset or post_reset callbacks), its ->remove routine called usb_reset_device() -- thus nesting one reset call within another. Performing a reset as part of disconnect processing is a questionable practice at best. However, the bug report points out that the USB core does not have any protection against nested resets. Adding a reset_in_progress flag and testing it will prevent such errors in the future. Link: https://lore.kernel.org/all/CAB7eexKUpvX-JNiLzhXBDWgfg2T9e9_0Tw4HQ6keN==voRbP0g@mail.gmail.com/ Cc: stable@vger.kernel.org Reported-and-tested-by: Rondreis <linhaoguo86@gmail.com> Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Link: https://lore.kernel.org/r/YwkflDxvg0KWqyZK@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-27usb: hub: Add delay for SuperSpeed hub resume to let links transit to U0Kai-Heng Feng1-1/+4
[ Upstream commit 00558586382891540c59c9febc671062425a6e47 ] When a new USB device gets plugged to nested hubs, the affected hub, which connects to usb 2-1.4-port2, doesn't report there's any change, hence the nested hubs go back to runtime suspend like nothing happened: [ 281.032951] usb usb2: usb wakeup-resume [ 281.032959] usb usb2: usb auto-resume [ 281.032974] hub 2-0:1.0: hub_resume [ 281.033011] usb usb2-port1: status 0263 change 0000 [ 281.033077] hub 2-0:1.0: state 7 ports 4 chg 0000 evt 0000 [ 281.049797] usb 2-1: usb wakeup-resume [ 281.069800] usb 2-1: Waited 0ms for CONNECT [ 281.069810] usb 2-1: finish resume [ 281.070026] hub 2-1:1.0: hub_resume [ 281.070250] usb 2-1-port4: status 0203 change 0000 [ 281.070272] usb usb2-port1: resume, status 0 [ 281.070282] hub 2-1:1.0: state 7 ports 4 chg 0010 evt 0000 [ 281.089813] usb 2-1.4: usb wakeup-resume [ 281.109792] usb 2-1.4: Waited 0ms for CONNECT [ 281.109801] usb 2-1.4: finish resume [ 281.109991] hub 2-1.4:1.0: hub_resume [ 281.110147] usb 2-1.4-port2: status 0263 change 0000 [ 281.110234] usb 2-1-port4: resume, status 0 [ 281.110239] usb 2-1-port4: status 0203, change 0000, 10.0 Gb/s [ 281.110266] hub 2-1.4:1.0: state 7 ports 4 chg 0000 evt 0000 [ 281.110426] hub 2-1.4:1.0: hub_suspend [ 281.110565] usb 2-1.4: usb auto-suspend, wakeup 1 [ 281.130998] hub 2-1:1.0: hub_suspend [ 281.137788] usb 2-1: usb auto-suspend, wakeup 1 [ 281.142935] hub 2-0:1.0: state 7 ports 4 chg 0000 evt 0000 [ 281.177828] usb 2-1: usb wakeup-resume [ 281.197839] usb 2-1: Waited 0ms for CONNECT [ 281.197850] usb 2-1: finish resume [ 281.197984] hub 2-1:1.0: hub_resume [ 281.198203] usb 2-1-port4: status 0203 change 0000 [ 281.198228] usb usb2-port1: resume, status 0 [ 281.198237] hub 2-1:1.0: state 7 ports 4 chg 0010 evt 0000 [ 281.217835] usb 2-1.4: usb wakeup-resume [ 281.237834] usb 2-1.4: Waited 0ms for CONNECT [ 281.237845] usb 2-1.4: finish resume [ 281.237990] hub 2-1.4:1.0: hub_resume [ 281.238067] usb 2-1.4-port2: status 0263 change 0000 [ 281.238148] usb 2-1-port4: resume, status 0 [ 281.238152] usb 2-1-port4: status 0203, change 0000, 10.0 Gb/s [ 281.238166] hub 2-1.4:1.0: state 7 ports 4 chg 0000 evt 0000 [ 281.238385] hub 2-1.4:1.0: hub_suspend [ 281.238523] usb 2-1.4: usb auto-suspend, wakeup 1 [ 281.258076] hub 2-1:1.0: hub_suspend [ 281.265744] usb 2-1: usb auto-suspend, wakeup 1 [ 281.285976] hub 2-0:1.0: hub_suspend [ 281.285988] usb usb2: bus auto-suspend, wakeup 1 USB 3.2 spec, 9.2.5.4 "Changing Function Suspend State" says that "If the link is in a non-U0 state, then the device must transition the link to U0 prior to sending the remote wake message", but the hub only transits the link to U0 after signaling remote wakeup. So be more forgiving and use a 20ms delay to let the link transit to U0 for remote wakeup. Suggested-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> Link: https://lore.kernel.org/r/20211215120108.336597-1-kai.heng.feng@canonical.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-16USB: core: Fix bug in resuming hub's handling of wakeup requestsAlan Stern1-1/+1
commit 0f663729bb4afc92a9986b66131ebd5b8a9254d1 upstream. Bugzilla #213839 reports a 7-port hub that doesn't work properly when devices are plugged into some of the ports; the kernel goes into an unending disconnect/reinitialize loop as shown in the bug report. This "7-port hub" comprises two four-port hubs with one plugged into the other; the failures occur when a device is plugged into one of the downstream hub's ports. (These hubs have other problems too. For example, they bill themselves as USB-2.0 compliant but they only run at full speed.) It turns out that the failures are caused by bugs in both the kernel and the hub. The hub's bug is that it reports a different bmAttributes value in its configuration descriptor following a remote wakeup (0xe0 before, 0xc0 after -- the wakeup-support bit has changed). The kernel's bug is inside the hub driver's resume handler. When hub_activate() sees that one of the hub's downstream ports got a wakeup request from a child device, it notes this fact by setting the corresponding bit in the hub->change_bits variable. But this variable is meant for connection changes, not wakeup events; setting it causes the driver to believe the downstream port has been disconnected and then connected again (in addition to having received a wakeup request). Because of this, the hub driver then tries to check whether the device currently plugged into the downstream port is the same as the device that had been attached there before. Normally this check succeeds and wakeup handling continues with no harm done (which is why the bug remained undetected until now). But with these dodgy hubs, the check fails because the config descriptor has changed. This causes the hub driver to reinitialize the child device, leading to the disconnect/reinitialize loop described in the bug report. The proper way to note reception of a downstream wakeup request is to set a bit in the hub->event_bits variable instead of hub->change_bits. That way the hub driver will realize that something has happened to the port but will not think the port and child device have been disconnected. This patch makes that change. Cc: <stable@vger.kernel.org> Tested-by: Jonathan McDowell <noodles@earth.li> Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Link: https://lore.kernel.org/r/YdCw7nSfWYPKWQoD@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-01usb: hub: Fix locking issues with address0_mutexMathias Nyman1-8/+12
commit 6cca13de26eea6d32a98d96d916a048d16a12822 upstream. Fix the circular lock dependency and unbalanced unlock of addess0_mutex introduced when fixing an address0_mutex enumeration retry race in commit ae6dc22d2d1 ("usb: hub: Fix usb enumeration issue due to address0 race") Make sure locking order between port_dev->status_lock and address0_mutex is correct, and that address0_mutex is not unlocked in hub_port_connect "done:" codepath which may be reached without locking address0_mutex Fixes: 6ae6dc22d2d1 ("usb: hub: Fix usb enumeration issue due to address0 race") Cc: <stable@vger.kernel.org> Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: Hans de Goede <hdegoede@redhat.com> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20211123101656.1113518-1-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-01usb: hub: Fix usb enumeration issue due to address0 raceMathias Nyman1-3/+11
commit 6ae6dc22d2d1ce6aa77a6da8a761e61aca216f8b upstream. xHC hardware can only have one slot in default state with address 0 waiting for a unique address at a time, otherwise "undefined behavior may occur" according to xhci spec 5.4.3.4 The address0_mutex exists to prevent this across both xhci roothubs. If hub_port_init() fails, it may unlock the mutex and exit with a xhci slot in default state. If the other xhci roothub calls hub_port_init() at this point we end up with two slots in default state. Make sure the address0_mutex protects the slot default state across hub_port_init() retries, until slot is addressed or disabled. Note, one known minor case is not fixed by this patch. If device needs to be reset during resume, but fails all hub_port_init() retries in usb_reset_and_verify_device(), then it's possible the slot is still left in default state when address0_mutex is unlocked. Cc: <stable@vger.kernel.org> Fixes: 638139eb95d2 ("usb: hub: allow to process more usb hub events in parallel") Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20211115221630.871204-1-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-28usb: hub: Fix link power management max exit latency (MEL) calculationsMathias Nyman1-24/+28
commit 1bf2761c837571a66ec290fb66c90413821ffda2 upstream. Maximum Exit Latency (MEL) value is used by host to know how much in advance it needs to start waking up a U1/U2 suspended link in order to service a periodic transfer in time. Current MEL calculation only includes the time to wake up the path from U1/U2 to U0. This is called tMEL1 in USB 3.1 section C 1.5.2 Total MEL = tMEL1 + tMEL2 +tMEL3 + tMEL4 which should additinally include: - tMEL2 which is the time it takes for PING message to reach device - tMEL3 time for device to process the PING and submit a PING_RESPONSE - tMEL4 time for PING_RESPONSE to traverse back upstream to host. Add the missing tMEL2, tMEL3 and tMEL4 to MEL calculation. Cc: <stable@kernel.org> # v3.5 Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210715150122.1995966-1-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-28usb: hub: Disable USB 3 device initiated lpm if exit latency is too highMathias Nyman1-12/+56
commit 1b7f56fbc7a1b66967b6114d1b5f5a257c3abae6 upstream. The device initiated link power management U1/U2 states should not be enabled in case the system exit latency plus one bus interval (125us) is greater than the shortest service interval of any periodic endpoint. This is the case for both U1 and U2 sytstem exit latencies and link states. See USB 3.2 section 9.4.9 "Set Feature" for more details Note, before this patch the host and device initiated U1/U2 lpm states were both enabled with lpm. After this patch it's possible to end up with only host inititated U1/U2 lpm in case the exit latencies won't allow device initiated lpm. If this case we still want to set the udev->usb3_lpm_ux_enabled flag so that sysfs users can see the link may go to U1/U2. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20210715150122.1995966-2-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-23usb: core: hub: Disable autosuspend for Cypress CY7C65632Andrew Lunn1-0/+7
commit a7d8d1c7a7f73e780aa9ae74926ae5985b2f895f upstream. The Cypress CY7C65632 appears to have an issue with auto suspend and detecting devices, not too dissimilar to the SMSC 5534B hub. It is easiest to reproduce by connecting multiple mass storage devices to the hub at the same time. On a Lenovo Yoga, around 1 in 3 attempts result in the devices not being detected. It is however possible to make them appear using lsusb -v. Disabling autosuspend for this hub resolves the issue. Fixes: 1208f9e1d758 ("USB: hub: Fix the broken detection of USB3 device in SMSC hub") Cc: stable@vger.kernel.org Signed-off-by: Andrew Lunn <andrew@lunn.ch> Link: https://lore.kernel.org/r/20210614155524.2228800-1-andrew@lunn.ch Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-19usb: core: hub: fix race condition about TRSMRCY of resumeChunfeng Yun1-3/+3
commit 975f94c7d6c306b833628baa9aec3f79db1eb3a1 upstream. This may happen if the port becomes resume status exactly when usb_port_resume() gets port status, it still need provide a TRSMCRY time before access the device. CC: <stable@vger.kernel.org> Reported-by: Tianping Fang <tianping.fang@mediatek.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com> Link: https://lore.kernel.org/r/20210512020738.52961-1-chunfeng.yun@mediatek.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-11usb: core: hub: Fix PM reference leak in usb_port_resume()Bixuan Cui1-1/+1
[ Upstream commit 025f97d188006eeee4417bb475a6878d1e0eed3f ] pm_runtime_get_sync will increment pm usage counter even it failed. thus a pairing decrement is needed. Fix it by replacing it with pm_runtime_resume_and_get to keep usage counter balanced. Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Bixuan Cui <cuibixuan@huawei.com> Link: https://lore.kernel.org/r/20210408130831.56239-1-cuibixuan@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-02USB: hub: Add Kconfig option to reduce number of port initialization retriesAlan Stern1-1/+12
Description based on one by Yasushi Asano: According to 6.7.22 A-UUT “Device No Response” for connection timeout of USB OTG and EH automated compliance plan v1.2, enumeration failure has to be detected within 30 seconds. However, the old and new enumeration schemes each make a total of 12 attempts, and each attempt can take 5 seconds to time out, so the PET test fails. This patch adds a new Kconfig option (CONFIG_USB_FEW_INIT_RETRIES); when the option is set all the initialization retry loops except the outermost are reduced to a single iteration. This reduces the total number of attempts to four, allowing Linux hosts to pass the PET test. The new option is disabled by default to preserve the existing behavior. The reduced number of retries may fail to initialize a few devices that currently do work, but for the most part there should be no change. And in cases where the initialization does fail, it will fail much more quickly. Reported-and-tested-by: yasushi asano <yazzep@gmail.com> Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Link: https://lore.kernel.org/r/20200928152217.GB134701@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-02USB: hub: Clean up use of port initialization schemes and retriesAlan Stern1-23/+26
The SET_CONFIG_TRIES macro in hub.c is badly named; it controls the number of port-initialization retry attempts rather than the number of Set-Configuration attempts. Furthermore, the USE_NEW_SCHEME macro and use_new_scheme() function are written in a very confusing manner, making it almost impossible to figure out exactly what they do or check that they are correct. This patch renames SET_CONFIG_TRIES to PORT_INIT_TRIES, removes USE_NEW_SCHEME entirely, and rewrites use_new_scheme() to be much more transparent, with added comments explaining how it works. The patch also pulls the single call site of use_new_scheme() out from the Get-Descriptor retry loop (where it returns the same value each time) and renames the local variable used to store the result. The overall effect is a minor cleanup. However, there is one functional change: If the "use_both_schemes" module parameter isn't set (by default it is set), the existing code does only two retry iterations. After this patch it will always perform four, regardless of the parameter's value. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Link: https://lore.kernel.org/r/20200928152050.GA134701@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-25Revert "USB: core: hub.c: use usb_control_msg_send() in a few places"Oliver Neukum1-40/+59
This reverts commit d6a499249543356002a1efbb26254c7272e62f4c. Control messages are needed in contexts when memory allocations are restricted, such as handling device resets and runtime PM. For this reason the control message API internally uses GFP_NOIO. This is a band aid introduced because when we recognized the issue, the call chains were highly convoluted. Continuing this trend is not a good idea. So I am shooting the whole kennel here. Signed-off-by: Oliver Neukum <oneukum@suse.com> Link: https://lore.kernel.org/r/20200923134348.23862-2-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-16USB: core: hub.c: use usb_control_msg_send() in a few placesGreg Kroah-Hartman1-59/+40
There are a few calls to usb_control_msg() that can be converted to use usb_control_msg_send() instead, so do that in order to make the error checking a bit simpler and the code smaller. Reviewed-by: Alan Stern <stern@rowland.harvard.edu> Link: https://lore.kernel.org/r/20200914153756.3412156-5-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-24treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva1-1/+1
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-07-10usb: Use fallthrough pseudo-keywordGustavo A. R. Silva1-1/+1
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Link: https://lore.kernel.org/r/20200707195607.GA4198@embeddedor Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-19USB: OTG: rename product list of devicesGreg Kroah-Hartman1-2/+2
Rename the list of specific devices that an OTG device could support to make it more obvious as to what this list is for and what it is doing. Also rename the configuration option to make it more obvious as well. Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Paul Burton <paulburton@kernel.org> Cc: "Diego Elio Pettenò" <flameeyes@flameeyes.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Krzysztof Kozlowski <krzk@kernel.org> Cc: "Philippe Mathieu-Daudé" <f4bug@amsat.org> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Eugeniu Rosca <erosca@de.adit-jv.com> Cc: Qi Zhou <atmgnd@outlook.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Hardik Gajjar <hgajjar@de.adit-jv.com> Cc: Harry Pan <harry.pan@intel.com> Cc: David Heinzelmann <heinzelmann.david@gmail.com> Cc: Nishad Kamdar <nishadkamdar@gmail.com> Link: https://lore.kernel.org/r/20200618094300.1887727-9-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-19USB: rename USB OTG hub configuration optionGreg Kroah-Hartman1-1/+1
The USB OTG code has the ability to disable external hubs, but the configuration option for it is oddly named. Rename it to be more obvious as to what it does. Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Bin Liu <b-liu@ti.com> Cc: Paul Cercueil <paul@crapouillou.net> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Eugeniu Rosca <erosca@de.adit-jv.com> Cc: Kai-Heng Feng <kai.heng.feng@canonical.com> Cc: David Heinzelmann <heinzelmann.david@gmail.com> Cc: "Lee, Chiasheng" <chiasheng.lee@intel.com> Cc: Keiya Nobuta <nobuta.keiya@fujitsu.com> Cc: Hardik Gajjar <hgajjar@de.adit-jv.com> Link: https://lore.kernel.org/r/20200618094300.1887727-3-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-18Merge 5.7-rc6 into usb-nextGreg Kroah-Hartman1-1/+5
We need the USB fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-15usb: core: hub: limit HUB_QUIRK_DISABLE_AUTOSUSPEND to USB5534BEugeniu Rosca1-1/+5
On Tue, May 12, 2020 at 09:36:07PM +0800, Kai-Heng Feng wrote [1]: > This patch prevents my Raven Ridge xHCI from getting runtime suspend. The problem described in v5.6 commit 1208f9e1d758c9 ("USB: hub: Fix the broken detection of USB3 device in SMSC hub") applies solely to the USB5534B hub [2] present on the Kingfisher Infotainment Carrier Board, manufactured by Shimafuji Electric Inc [3]. Despite that, the aforementioned commit applied the quirk to _all_ hubs carrying vendor ID 0x424 (i.e. SMSC), of which there are more [4] than initially expected. Consequently, the quirk is now enabled on platforms carrying SMSC/Microchip hub models which potentially don't exhibit the original issue. To avoid reports like [1], further limit the quirk's scope to USB5534B [2], by employing both Vendor and Product ID checks. Tested on H3ULCB + Kingfisher rev. M05. [1] https://lore.kernel.org/linux-renesas-soc/73933975-6F0E-40F5-9584-D2B8F615C0F3@canonical.com/ [2] https://www.microchip.com/wwwproducts/en/USB5534B [3] http://www.shimafuji.co.jp/wp/wp-content/uploads/2018/08/SBEV-RCAR-KF-M06Board_HWSpecificationEN_Rev130.pdf [4] https://devicehunt.com/search/type/usb/vendor/0424/device/any Fixes: 1208f9e1d758c9 ("USB: hub: Fix the broken detection of USB3 device in SMSC hub") Cc: stable@vger.kernel.org # v4.14+ Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Hardik Gajjar <hgajjar@de.adit-jv.com> Cc: linux-renesas-soc@vger.kernel.org Cc: linux-usb@vger.kernel.org Reported-by: Kai-Heng Feng <kai.heng.feng@canonical.com> Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com> Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com> Link: https://lore.kernel.org/r/20200514220246.13290-1-erosca@de.adit-jv.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-28usb: core: hub: use true,false for bool variableJason Yan1-1/+1
Fix the following coccicheck warning: drivers/usb/core/hub.c:95:12-28: WARNING: Assignment of 0/1 to bool variable Signed-off-by: Jason Yan <yanaijie@huawei.com> Link: https://lore.kernel.org/r/20200426094147.23467-1-yanaijie@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-23USB: hub: Revert commit bd0e6c9614b9 ("usb: hub: try old enumeration scheme ↵Alan Stern1-3/+1
first for high speed devices") Commit bd0e6c9614b9 ("usb: hub: try old enumeration scheme first for high speed devices") changed the way the hub driver enumerates high-speed devices. Instead of using the "new" enumeration scheme first and switching to the "old" scheme if that doesn't work, we start with the "old" scheme. In theory this is better because the "old" scheme is slightly faster -- it involves resetting the device only once instead of twice. However, for a long time Windows used only the "new" scheme. Zeng Tao said that Windows 8 and later use the "old" scheme for high-speed devices, but apparently there are some devices that don't like it. William Bader reports that the Ricoh webcam built into his Sony Vaio laptop not only doesn't enumerate under the "old" scheme, it gets hung up so badly that it won't then enumerate under the "new" scheme! Only a cold reset will fix it. Therefore we will revert the commit and go back to trying the "new" scheme first for high-speed devices. Reported-and-tested-by: William Bader <williambader@hotmail.com> Ref: https://bugzilla.kernel.org/show_bug.cgi?id=207219 Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Fixes: bd0e6c9614b9 ("usb: hub: try old enumeration scheme first for high speed devices") CC: Zeng Tao <prime.zeng@hisilicon.com> CC: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/Pine.LNX.4.44L0.2004221611230.11262-100000@iolanthe.rowland.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-23USB: hub: Fix handling of connect changes during sleepAlan Stern1-0/+14
Commit 8099f58f1ecd ("USB: hub: Don't record a connect-change event during reset-resume") wasn't very well conceived. The problem it tried to fix was that if a connect-change event occurred while the system was asleep (such as a device disconnecting itself from the bus when it is suspended and then reconnecting when it resumes) requiring a reset-resume during the system wakeup transition, the hub port's change_bit entry would remain set afterward. This would cause the hub driver to believe another connect-change event had occurred after the reset-resume, which was wrong and would lead the driver to send unnecessary requests to the device (which could interfere with a firmware update). The commit tried to fix this by not setting the change_bit during the wakeup. But this was the wrong thing to do; it means that when a device is unplugged while the system is asleep, the hub driver doesn't realize anything has happened: The change_bit flag which would tell it to handle the disconnect event is clear. The commit needs to be reverted and the problem fixed in a different way. Fortunately an alternative solution was noted in the commit's Changelog: We can continue to set the change_bit entry in hub_activate() but then clear it when a reset-resume occurs. That way the the hub driver will see the change_bit when a device is disconnected but won't see it when the device is still present. That's what this patch does. Reported-and-tested-by: Peter Chen <peter.chen@nxp.com> Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Fixes: 8099f58f1ecd ("USB: hub: Don't record a connect-change event during reset-resume") Tested-by: Paul Zimmerman <pauldzim@gmail.com> CC: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/Pine.LNX.4.44L0.2004221602480.11262-100000@iolanthe.rowland.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-04usb: core: hub: do error out if usb_autopm_get_interface() failsEugeniu Rosca1-1/+5
Reviewing a fresh portion of coverity defects in USB core (specifically CID 1458999), Alan Stern noted below in [1]: On Tue, Feb 25, 2020 at 02:39:23PM -0500, Alan Stern wrote: > A revised search finds line 997 in drivers/usb/core/hub.c and lines > 216, 269 in drivers/usb/core/port.c. (I didn't try looking in any > other directories.) AFAICT all three of these should check the > return value, although a error message in the kernel log probably > isn't needed. Factor out the usb_remove_device() change into a standalone patch to allow conflict-free integration on top of the earliest stable branches. [1] https://lore.kernel.org/lkml/Pine.LNX.4.44L0.2002251419120.1485-100000@iolanthe.rowland.org Fixes: 253e05724f9230 ("USB: add a "remove hardware" sysfs attribute") Cc: stable@vger.kernel.org # v2.6.33+ Suggested-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Link: https://lore.kernel.org/r/20200226175036.14946-2-erosca@de.adit-jv.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-04usb: core: hub: fix unhandled return by employing a void functionEugeniu Rosca1-1/+1
Address below Coverity complaint (Feb 25, 2020, 8:06 AM CET): *** CID 1458999: Error handling issues (CHECKED_RETURN) /drivers/usb/core/hub.c: 1869 in hub_probe() 1863 1864 if (id->driver_info & HUB_QUIRK_CHECK_PORT_AUTOSUSPEND) 1865 hub->quirk_check_port_auto_suspend = 1; 1866 1867 if (id->driver_info & HUB_QUIRK_DISABLE_AUTOSUSPEND) { 1868 hub->quirk_disable_autosuspend = 1; >>> CID 1458999: Error handling issues (CHECKED_RETURN) >>> Calling "usb_autopm_get_interface" without checking return value (as is done elsewhere 97 out of 111 times). 1869 usb_autopm_get_interface(intf); 1870 } 1871 1872 if (hub_configure(hub, &desc->endpoint[0].desc) >= 0) 1873 return 0; 1874 Rather than checking the return value of 'usb_autopm_get_interface()', switch to the usb_autopm_get_interface_no_resume() API, as per: On Tue, Feb 25, 2020 at 10:32:32AM -0500, Alan Stern wrote: ------ 8< ------ > This change (i.e. 'ret = usb_autopm_get_interface') is not necessary, > because the resume operation cannot fail at this point (interfaces > are always powered-up during probe). A better solution would be to > call usb_autopm_get_interface_no_resume() instead. ------ 8< ------ Fixes: 1208f9e1d758c9 ("USB: hub: Fix the broken detection of USB3 device in SMSC hub") Cc: Hardik Gajjar <hgajjar@de.adit-jv.com> Cc: stable@vger.kernel.org # v4.14+ Reported-by: scan-admin@coverity.com Suggested-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Link: https://lore.kernel.org/r/20200226175036.14946-1-erosca@de.adit-jv.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-10USB: hub: Don't record a connect-change event during reset-resumeAlan Stern1-5/+0
Paul Zimmerman reports that his USB Bluetooth adapter sometimes crashes following system resume, when it receives a Get-Device-Descriptor request while it is busy doing something else. Such a request was added by commit a4f55d8b8c14 ("usb: hub: Check device descriptor before resusciation"). It gets sent when the hub driver's work thread checks whether a connect-change event on an enabled port really indicates a new device has been connected, as opposed to an old device momentarily disconnecting and then reconnecting (which can happen with xHCI host controllers, since they automatically enable connected ports). The same kind of thing occurs when a port's power session is lost during system suspend. When the system wakes up it sees a connect-change event on the port, and if the child device's persist_enabled flag was set then hub_activate() sets the device's reset_resume flag as well as the port's bit in hub->change_bits. The reset-resume code then takes responsibility for checking that the same device is still attached to the port, and it does this as part of the device's resume pathway. By the time the hub driver's work thread starts up again, the device has already been fully reinitialized and is busy doing its own thing. There's no need for the work thread to do the same check a second time, and in fact this unnecessary check is what caused the problem that Paul observed. Note that performing the unnecessary check is not actually a bug. Devices are supposed to be able to send descriptors back to the host even when they are busy doing something else. The underlying cause of Paul's problem lies in his Bluetooth adapter. Nevertheless, we shouldn't perform the same check twice in a row -- and as a nice side benefit, removing the extra check allows the Bluetooth adapter to work more reliably. The work thread performs its check when it sees that the port's bit is set in hub->change_bits. In this situation that bit is interpreted as though a connect-change event had occurred on the port _after_ the reset-resume, which is not what actually happened. One possible fix would be to make the reset-resume code clear the port's bit in hub->change_bits. But it seems simpler to just avoid setting the bit during hub_activate() in the first place. That's what this patch does. (Proving that the patch is correct when CONFIG_PM is disabled requires a little thought. In that setting hub_activate() will be called only for initialization and resets, since there won't be any resumes or reset-resumes. During initialization and hub resets the hub doesn't have any child devices, and so this code path never gets executed.) Reported-and-tested-by: Paul Zimmerman <pauldzim@gmail.com> Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Link: https://marc.info/?t=157949360700001&r=1&w=2 CC: David Heinzelmann <heinzelmann.david@gmail.com> CC: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/Pine.LNX.4.44L0.2001311037460.1577-100000@iolanthe.rowland.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-10USB: hub: Fix the broken detection of USB3 device in SMSC hubHardik Gajjar1-0/+15
Renesas R-Car H3ULCB + Kingfisher Infotainment Board is either not able to detect the USB3.0 mass storage devices or is detecting those as USB2.0 high speed devices. The explanation given by Renesas is that, due to a HW issue, the XHCI driver does not wake up after going to sleep on connecting a USB3.0 device. In order to mitigate that, disable the auto-suspend feature specifically for SMSC hubs from hub_probe() function, as a quirk. Renesas Kingfisher Infotainment Board has two USB3.0 ports (CN2) which are connected via USB5534B 4-port SuperSpeed/Hi-Speed, low-power, configurable hub controller. [1] SanDisk USB 3.0 device detected as USB-2.0 before the patch [ 74.036390] usb 5-1.1: new high-speed USB device number 4 using xhci-hcd [ 74.061598] usb 5-1.1: New USB device found, idVendor=0781, idProduct=5581, bcdDevice= 1.00 [ 74.069976] usb 5-1.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [ 74.077303] usb 5-1.1: Product: Ultra [ 74.080980] usb 5-1.1: Manufacturer: SanDisk [ 74.085263] usb 5-1.1: SerialNumber: 4C530001110208116550 [2] SanDisk USB 3.0 device detected as USB-3.0 after the patch [ 34.565078] usb 6-1.1: new SuperSpeed Gen 1 USB device number 3 using xhci-hcd [ 34.588719] usb 6-1.1: New USB device found, idVendor=0781, idProduct=5581, bcdDevice= 1.00 [ 34.597098] usb 6-1.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [ 34.604430] usb 6-1.1: Product: Ultra [ 34.608110] usb 6-1.1: Manufacturer: SanDisk [ 34.612397] usb 6-1.1: SerialNumber: 4C530001110208116550 Suggested-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Hardik Gajjar <hgajjar@de.adit-jv.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/1580989763-32291-1-git-send-email-hgajjar@de.adit-jv.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-15usb: core: hub: Improved device recognition on remote wakeupKeiya Nobuta1-0/+1
If hub_activate() is called before D+ has stabilized after remote wakeup, the following situation might occur: __ ___________________ / \ / D+ __/ \__/ Hub _______________________________ | ^ ^ ^ | | | | Host _____v__|___|___________|______ | | | | | | | \-- Interrupt Transfer (*3) | | \-- ClearPortFeature (*2) | \-- GetPortStatus (*1) \-- Host detects remote wakeup - D+ goes high, Host starts running by remote wakeup - D+ is not stable, goes low - Host requests GetPortStatus at (*1) and gets the following hub status: - Current Connect Status bit is 0 - Connect Status Change bit is 1 - D+ stabilizes, goes high - Host requests ClearPortFeature and thus Connect Status Change bit is cleared at (*2) - After waiting 100 ms, Host starts the Interrupt Transfer at (*3) - Since the Connect Status Change bit is 0, Hub returns NAK. In this case, port_event() is not called in hub_event() and Host cannot recognize device. To solve this issue, flag change_bits even if only Connect Status Change bit is 1 when got in the first GetPortStatus. This issue occurs rarely because it only if D+ changes during a very short time between GetPortStatus and ClearPortFeature. However, it is fatal if it occurs in embedded system. Signed-off-by: Keiya Nobuta <nobuta.keiya@fujitsu.com> Cc: stable <stable@vger.kernel.org> Acked-by: Alan Stern <stern@rowland.harvard.edu> Link: https://lore.kernel.org/r/20200109051448.28150-1-nobuta.keiya@fujitsu.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-08usb: missing parentheses in USE_NEW_SCHEMEQi Zhou1-1/+1
According to bd0e6c9614b9 ("usb: hub: try old enumeration scheme first for high speed devices") the kernel will try the old enumeration scheme first for high speed devices. This can happen when a high speed device is plugged in. But due to missing parentheses in the USE_NEW_SCHEME define, this logic can get messed up and the incorrect result happens. Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Qi Zhou <atmgnd@outlook.com> Link: https://lore.kernel.org/r/ht4mtag8ZP-HKEhD0KkJhcFnVlOFV8N8eNjJVRD9pDkkLUNhmEo8_cL_sl7xy9mdajdH-T8J3TFQsjvoYQT61NFjQXy469Ed_BbBw_x4S1E=@protonmail.com [ fixup changelog text - gregkh] Cc: stable <stable@vger.kernel.org> Fixes: bd0e6c9614b9 ("usb: hub: try old enumeration scheme first for high speed devices") Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-05usb, kcov: collect coverage from hub_eventAndrey Konovalov1-0/+5
Add kcov_remote_start()/kcov_remote_stop() annotations to the hub_event() function, which is responsible for processing events on USB buses, in particular events that happen during USB device enumeration. Since hub_event() is run in a global background kernel thread (see Documentation/dev-tools/kcov.rst for details), each USB bus gets a unique global handle from the USB subsystem kcov handle range. As the result kcov can now be used to collect coverage from events that happen on a particular USB bus. [akpm@linux-foundation.org: avoid patch conflicts to make life easier for Andrew] Link: http://lkml.kernel.org/r/de4fe1c219db2d002d905dc1736e2a3bfa1db997.1572366574.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Alexander Potapenko <glider@google.com> Cc: Anders Roxell <anders.roxell@linaro.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Windsor <dwindsor@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Elena Reshetova <elena.reshetova@intel.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Marco Elver <elver@google.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-11-07usb: Allow USB device to be warm reset in suspended stateKai-Heng Feng1-3/+2
On Dell WD15 dock, sometimes USB ethernet cannot be detected after plugging cable to the ethernet port, the hub and roothub get runtime resumed and runtime suspended immediately: ... [ 433.315169] xhci_hcd 0000:3a:00.0: hcd_pci_runtime_resume: 0 [ 433.315204] usb usb4: usb auto-resume [ 433.315226] hub 4-0:1.0: hub_resume [ 433.315239] xhci_hcd 0000:3a:00.0: Get port status 4-1 read: 0x10202e2, return 0x10343 [ 433.315264] usb usb4-port1: status 0343 change 0001 [ 433.315279] xhci_hcd 0000:3a:00.0: clear port1 connect change, portsc: 0x10002e2 [ 433.315293] xhci_hcd 0000:3a:00.0: Get port status 4-2 read: 0x2a0, return 0x2a0 [ 433.317012] xhci_hcd 0000:3a:00.0: xhci_hub_status_data: stopping port polling. [ 433.422282] xhci_hcd 0000:3a:00.0: Get port status 4-1 read: 0x10002e2, return 0x343 [ 433.422307] usb usb4-port1: do warm reset [ 433.422311] usb 4-1: device reset not allowed in state 8 [ 433.422339] hub 4-0:1.0: state 7 ports 2 chg 0002 evt 0000 [ 433.422346] xhci_hcd 0000:3a:00.0: Get port status 4-1 read: 0x10002e2, return 0x343 [ 433.422356] usb usb4-port1: do warm reset [ 433.422358] usb 4-1: device reset not allowed in state 8 [ 433.422428] xhci_hcd 0000:3a:00.0: set port remote wake mask, actual port 0 status = 0xf0002e2 [ 433.422455] xhci_hcd 0000:3a:00.0: set port remote wake mask, actual port 1 status = 0xe0002a0 [ 433.422465] hub 4-0:1.0: hub_suspend [ 433.422475] usb usb4: bus auto-suspend, wakeup 1 [ 433.426161] xhci_hcd 0000:3a:00.0: xhci_hub_status_data: stopping port polling. [ 433.466209] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting [ 433.510204] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting [ 433.554051] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting [ 433.598235] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting [ 433.642154] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting [ 433.686204] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting [ 433.730205] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting [ 433.774203] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting [ 433.818207] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting [ 433.862040] xhci_hcd 0000:3a:00.0: port 0 polling in bus suspend, waiting [ 433.862053] xhci_hcd 0000:3a:00.0: xhci_hub_status_data: stopping port polling. [ 433.862077] xhci_hcd 0000:3a:00.0: xhci_suspend: stopping port polling. [ 433.862096] xhci_hcd 0000:3a:00.0: // Setting command ring address to 0x8578fc001 [ 433.862312] xhci_hcd 0000:3a:00.0: hcd_pci_runtime_suspend: 0 [ 433.862445] xhci_hcd 0000:3a:00.0: PME# enabled [ 433.902376] xhci_hcd 0000:3a:00.0: restoring config space at offset 0xc (was 0x0, writing 0x20) [ 433.902395] xhci_hcd 0000:3a:00.0: restoring config space at offset 0x4 (was 0x100000, writing 0x100403) [ 433.902490] xhci_hcd 0000:3a:00.0: PME# disabled [ 433.902504] xhci_hcd 0000:3a:00.0: enabling bus mastering [ 433.902547] xhci_hcd 0000:3a:00.0: // Setting command ring address to 0x8578fc001 [ 433.902649] pcieport 0000:00:1b.0: PME: Spurious native interrupt! [ 433.902839] xhci_hcd 0000:3a:00.0: Port change event, 4-1, id 3, portsc: 0xb0202e2 [ 433.902842] xhci_hcd 0000:3a:00.0: resume root hub [ 433.902845] xhci_hcd 0000:3a:00.0: handle_port_status: starting port polling. [ 433.902877] xhci_hcd 0000:3a:00.0: xhci_resume: starting port polling. [ 433.902889] xhci_hcd 0000:3a:00.0: xhci_hub_status_data: stopping port polling. [ 433.902891] xhci_hcd 0000:3a:00.0: hcd_pci_runtime_resume: 0 [ 433.902919] usb usb4: usb wakeup-resume [ 433.902942] usb usb4: usb auto-resume [ 433.902966] hub 4-0:1.0: hub_resume ... As Mathias pointed out, the hub enters Cold Attach Status state and requires a warm reset. However usb_reset_device() bails out early when the device is in suspended state, as its callers port_event() and hub_event() don't always resume the device. Since there's nothing wrong to reset a suspended device, allow usb_reset_device() to do so to solve the issue. Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20191106062710.29880-1-kai.heng.feng@canonical.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-10usb: hub: Check device descriptor before resusciationDavid Heinzelmann1-85/+111
If a device connected to an xHCI host controller disconnects from the USB bus and then reconnects, e.g. triggered by a firmware update, then the host controller automatically activates the connection and the port is enabled. The implementation of hub_port_connect_change() assumes that if the port is enabled then nothing has changed. There is no check if the USB descriptors have changed. As a result, the kernel's internal copy of the descriptors ends up being incorrect and the device doesn't work properly anymore. The solution to the problem is for hub_port_connect_change() always to check whether the device's descriptors have changed before resuscitating an enabled port. Signed-off-by: David Heinzelmann <heinzelmann.david@gmail.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Link: https://lore.kernel.org/r/20191009044647.24536-1-heinzelmann.david@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-03usb: Handle USB3 remote wakeup for LPM enabled devices correctlyLee, Chiasheng1-2/+5
With Link Power Management (LPM) enabled USB3 links transition to low power U1/U2 link states from U0 state automatically. Current hub code detects USB3 remote wakeups by checking if the software state still shows suspended, but the link has transitioned from suspended U3 to enabled U0 state. As it takes some time before the hub thread reads the port link state after a USB3 wake notification, the link may have transitioned from U0 to U1/U2, and wake is not detected by hub code. Fix this by handling U1/U2 states in the same way as U0 in USB3 wakeup handling This patch should be added to stable kernels since 4.13 where LPM was kept enabled during suspend/resume Cc: <stable@vger.kernel.org> # v4.13+ Signed-off-by: Lee, Chiasheng <chiasheng.lee@intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-20USB: core: correct a spelling mistake in the commentHarry Pan1-1/+1
Fix a spelling typo in the function comment. Signed-off-by: Harry Pan <harry.pan@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05usb: Add devaddr in struct usb_deviceJim Lin1-1/+3
The Clear_TT_Buffer request sent to the hub includes the address of the LS/FS child device in wValue field. usb_hub_clear_tt_buffer() uses udev->devnum to set the address wValue. This won't work for devices connected to xHC. For other host controllers udev->devnum is the same as the address of the usb device, chosen and set by usb core. With xHC the controller hardware assigns the address, and won't be the same as devnum. Here we add devaddr in "struct usb_device" for usb_hub_clear_tt_buffer() to use. Signed-off-by: Jim Lin <jilin@nvidia.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21usb: core: hub: Disable hub-initiated U1/U2Thinh Nguyen1-12/+16
If the device rejects the control transfer to enable device-initiated U1/U2 entry, then the device will not initiate U1/U2 transition. To improve the performance, the downstream port should not initate transition to U1/U2 to avoid the delay from the device link command response (no packet can be transmitted while waiting for a response from the device). If the device has some quirks and does not implement U1/U2, it may reject all the link state change requests, and the downstream port may resend and flood the bus with more requests. This will affect the device performance even further. This patch disables the hub-initated U1/U2 if the device-initiated U1/U2 entry fails. Reference: USB 3.2 spec 7.2.4.2.3 Signed-off-by: Thinh Nguyen <thinhn@synopsys.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>