kernel/linux.git/drivers/usb/core/hub.c, branch v6.6.150

usb: hub: Don't try to recover devices lost during warm reset.

2025-07-24T06:53:21+00:00

commit 2521106fc732b0b75fd3555c689b1ed1d29d273c upstream. Hub driver warm-resets ports in SS.Inactive or Compliance mode to recover a possible connected device. The port reset code correctly detects if a connection is lost during reset, but hub driver port_event() fails to take this into account in some cases. port_event() ends up using stale values and assumes there is a connected device, and will try all means to recover it, including power-cycling the port. Details: This case was triggered when xHC host was suspended with DbC (Debug Capability) enabled and connected. DbC turns one xHC port into a simple usb debug device, allowing debugging a system with an A-to-A USB debug cable. xhci DbC code disables DbC when xHC is system suspended to D3, and enables it back during resume. We essentially end up with two hosts connected to each other during suspend, and, for a short while during resume, until DbC is enabled back. The suspended xHC host notices some activity on the roothub port, but can't train the link due to being suspended, so xHC hardware sets a CAS (Cold Attach Status) flag for this port to inform xhci host driver that the port needs to be warm reset once xHC resumes. CAS is xHCI specific, and not part of USB specification, so xhci driver tells usb core that the port has a connection and link is in compliance mode. Recovery from complinace mode is similar to CAS recovery. xhci CAS driver support that fakes a compliance mode connection was added in commit 8bea2bd37df0 ("usb: Add support for root hub port status CAS") Once xHCI resumes and DbC is enabled back, all activity on the xHC roothub host side port disappears. The hub driver will anyway think port has a connection and link is in compliance mode, and hub driver will try to recover it. The port power-cycle during recovery seems to cause issues to the active DbC connection. Fix this by clearing connect_change flag if hub_port_reset() returns -ENOTCONN, thus avoiding the whole unnecessary port recovery and initialization attempt. Cc: stable@vger.kernel.org Fixes: 8bea2bd37df0 ("usb: Add support for root hub port status CAS") Tested-by: Łukasz Bartosik Signed-off-by: Mathias Nyman Acked-by: Alan Stern Link: https://lore.kernel.org/r/20250623133947.3144608-1-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman

usb: hub: Fix flushing of delayed work used for post resume purposes

2025-07-24T06:53:21+00:00

commit 9bd9c8026341f75f25c53104eb7e656e357ca1a2 upstream. Delayed work that prevents USB3 hubs from runtime-suspending too early needed to be flushed in hub_quiesce() to resolve issues detected on QC SC8280XP CRD board during suspend resume testing. This flushing did however trigger new issues on Raspberry Pi 3B+, which doesn't have USB3 ports, and doesn't queue any post resume delayed work. The flushed 'hub->init_work' item is used for several purposes, and is originally initialized with a 'NULL' work function. The work function is also changed on the fly, which may contribute to the issue. Solve this by creating a dedicated delayed work item for post resume work, and flush that delayed work in hub_quiesce() Cc: stable Fixes: a49e1e2e785f ("usb: hub: Fix flushing and scheduling of delayed work that tunes runtime pm") Reported-by: Mark Brown Closes: https://lore.kernel.org/linux-usb/aF5rNp1l0LWITnEB@finisterre.sirena.org.uk Signed-off-by: Mathias Nyman Tested-by: Konrad Dybcio # SC8280XP CRD Tested-by: Mark Brown Link: https://lore.kernel.org/r/20250627164348.3982628-2-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman

usb: hub: Fix flushing and scheduling of delayed work that tunes runtime pm

2025-07-24T06:53:20+00:00

commit a49e1e2e785fb3621f2d748581881b23a364998a upstream. Delayed work to prevent USB3 hubs from runtime-suspending immediately after resume was added in commit 8f5b7e2bec1c ("usb: hub: fix detection of high tier USB3 devices behind suspended hubs"). This delayed work needs be flushed if system suspends, or hub needs to be quiesced for other reasons right after resume. Not flushing it triggered issues on QC SC8280XP CRD board during suspend/resume testing. Fix it by flushing the delayed resume work in hub_quiesce() The delayed work item that allow hub runtime suspend is also scheduled just before calling autopm get. Alan pointed out there is a small risk that work is run before autopm get, which would call autopm put before get, and mess up the runtime pm usage order. Swap the order of work sheduling and calling autopm get to solve this. Cc: stable Fixes: 8f5b7e2bec1c ("usb: hub: fix detection of high tier USB3 devices behind suspended hubs") Reported-by: Konrad Dybcio Closes: https://lore.kernel.org/linux-usb/acaaa928-832c-48ca-b0ea-d202d5cd3d6c@oss.qualcomm.com Reported-by: Alan Stern Closes: https://lore.kernel.org/linux-usb/c73fbead-66d7-497a-8fa1-75ea4761090a@rowland.harvard.edu Signed-off-by: Mathias Nyman Link: https://lore.kernel.org/r/20250626130102.3639861-2-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman

usb: hub: fix detection of high tier USB3 devices behind suspended hubs

2025-07-24T06:53:20+00:00

commit 8f5b7e2bec1c36578fdaa74a6951833541103e27 upstream. USB3 devices connected behind several external suspended hubs may not be detected when plugged in due to aggressive hub runtime pm suspend. The hub driver immediately runtime-suspends hubs if there are no active children or port activity. There is a delay between the wake signal causing hub resume, and driver visible port activity on the hub downstream facing ports. Most of the LFPS handshake, resume signaling and link training done on the downstream ports is not visible to the hub driver until completed, when device then will appear fully enabled and running on the port. This delay between wake signal and detectable port change is even more significant with chained suspended hubs where the wake signal will propagate upstream first. Suspended hubs will only start resuming downstream ports after upstream facing port resumes. The hub driver may resume a USB3 hub, read status of all ports, not yet see any activity, and runtime suspend back the hub before any port activity is visible. This exact case was seen when conncting USB3 devices to a suspended Thunderbolt dock. USB3 specification defines a 100ms tU3WakeupRetryDelay, indicating USB3 devices expect to be resumed within 100ms after signaling wake. if not then device will resend the wake signal. Give the USB3 hubs twice this time (200ms) to detect any port changes after resume, before allowing hub to runtime suspend again. Cc: stable Fixes: 2839f5bcfcfc ("USB: Turn on auto-suspend for USB 3.0 hubs.") Acked-by: Alan Stern Signed-off-by: Mathias Nyman Link: https://lore.kernel.org/r/20250611112441.2267883-1-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman

usb: Flush altsetting 0 endpoints before reinitializating them after reset.

2025-06-19T13:28:46+00:00

commit 89bb3dc13ac29a563f4e4c555e422882f64742bd upstream. usb core avoids sending a Set-Interface altsetting 0 request after device reset, and instead relies on calling usb_disable_interface() and usb_enable_interface() to flush and reset host-side of those endpoints. xHCI hosts allocate and set up endpoint ring buffers and host_ep->hcpriv during usb_hcd_alloc_bandwidth() callback, which in this case is called before flushing the endpoint in usb_disable_interface(). Call usb_disable_interface() before usb_hcd_alloc_bandwidth() to ensure URBs are flushed before new ring buffers for the endpoints are allocated. Otherwise host driver will attempt to find and remove old stale URBs from a freshly allocated new ringbuffer. Cc: stable Fixes: 4fe0387afa89 ("USB: don't send Set-Interface after reset") Signed-off-by: Mathias Nyman Link: https://lore.kernel.org/r/20250514132520.225345-1-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman

usb: hub: lack of clearing xHC resources

2025-03-13T11:58:33+00:00

commit 2b66ef84d0d2a0ea955b40bd306f5e3abbc5cf9c upstream. The xHC resources allocated for USB devices are not released in correct order after resuming in case when while suspend device was reconnected. This issue has been detected during the fallowing scenario: - connect hub HS to root port - connect LS/FS device to hub port - wait for enumeration to finish - force host to suspend - reconnect hub attached to root port - wake host For this scenario during enumeration of USB LS/FS device the Cadence xHC reports completion error code for xHC commands because the xHC resources used for devices has not been properly released. XHCI specification doesn't mention that device can be reset in any order so, we should not treat this issue as Cadence xHC controller bug. Similar as during disconnecting in this case the device resources should be cleared starting form the last usb device in tree toward the root hub. To fix this issue usbcore driver should call hcd->driver->reset_device for all USB devices connected to hub which was reconnected while suspending. Fixes: 3d82904559f4 ("usb: cdnsp: cdns3 Add main part of Cadence USBSSP DRD Driver") Cc: stable Signed-off-by: Pawel Laszczak Reviewed-by: Alan Stern Link: https://lore.kernel.org/r/PH7PR07MB953841E38C088678ACDCF6EEDDCC2@PH7PR07MB9538.namprd07.prod.outlook.com Signed-off-by: Greg Kroah-Hartman

USB: hub: Ignore non-compliant devices with too many configs or interfaces

2025-02-21T12:57:15+00:00

commit 2240fed37afbcdb5e8b627bc7ad986891100e05d upstream. Robert Morris created a test program which can cause usb_hub_to_struct_hub() to dereference a NULL or inappropriate pointer: Oops: general protection fault, probably for non-canonical address 0xcccccccccccccccc: 0000 [#1] SMP DEBUG_PAGEALLOC PTI CPU: 7 UID: 0 PID: 117 Comm: kworker/7:1 Not tainted 6.13.0-rc3-00017-gf44d154d6e3d #14 Hardware name: FreeBSD BHYVE/BHYVE, BIOS 14.0 10/17/2021 Workqueue: usb_hub_wq hub_event RIP: 0010:usb_hub_adjust_deviceremovable+0x78/0x110 ... Call Trace: ? die_addr+0x31/0x80 ? exc_general_protection+0x1b4/0x3c0 ? asm_exc_general_protection+0x26/0x30 ? usb_hub_adjust_deviceremovable+0x78/0x110 hub_probe+0x7c7/0xab0 usb_probe_interface+0x14b/0x350 really_probe+0xd0/0x2d0 ? __pfx___device_attach_driver+0x10/0x10 __driver_probe_device+0x6e/0x110 driver_probe_device+0x1a/0x90 __device_attach_driver+0x7e/0xc0 bus_for_each_drv+0x7f/0xd0 __device_attach+0xaa/0x1a0 bus_probe_device+0x8b/0xa0 device_add+0x62e/0x810 usb_set_configuration+0x65d/0x990 usb_generic_driver_probe+0x4b/0x70 usb_probe_device+0x36/0xd0 The cause of this error is that the device has two interfaces, and the hub driver binds to interface 1 instead of interface 0, which is where usb_hub_to_struct_hub() looks. We can prevent the problem from occurring by refusing to accept hub devices that violate the USB spec by having more than one configuration or interface. Reported-and-tested-by: Robert Morris Cc: stable Closes: https://lore.kernel.org/linux-usb/95564.1737394039@localhost/ Signed-off-by: Alan Stern Link: https://lore.kernel.org/r/c27f3bf4-63d8-4fb5-ac82-09e3cd19f61c@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman

usb: core: fix pipe creation for get_bMaxPacketSize0

2025-02-21T12:57:14+00:00

commit 4aac0db5a0ebc599d4ad9bf5ebab78afa1f33e10 upstream. When usb_control_msg is used in the get_bMaxPacketSize0 function, the USB pipe does not include the endpoint device number. This can cause failures when a usb hub port is reinitialized after encountering a bad cable connection. As a result, the system logs the following error messages: usb usb2-port1: cannot reset (err = -32) usb usb2-port1: Cannot enable. Maybe the USB cable is bad? usb usb2-port1: attempt power cycle usb 2-1: new high-speed USB device number 5 using ci_hdrc usb 2-1: device descriptor read/8, error -71 The problem began after commit 85d07c556216 ("USB: core: Unite old scheme and new scheme descriptor reads"). There usb_get_device_descriptor was replaced with get_bMaxPacketSize0. Unlike usb_get_device_descriptor, the get_bMaxPacketSize0 function uses the macro usb_rcvaddr0pipe, which does not include the endpoint device number. usb_get_device_descriptor, on the other hand, used the macro usb_rcvctrlpipe, which includes the endpoint device number. By modifying the get_bMaxPacketSize0 function to use usb_rcvctrlpipe instead of usb_rcvaddr0pipe, the issue can be resolved. This change will ensure that the endpoint device number is included in the USB pipe, preventing reinitialization failures. If the endpoint has not set the device number yet, it will still work because the device number is 0 in udev. Cc: stable Fixes: 85d07c556216 ("USB: core: Unite old scheme and new scheme descriptor reads") Signed-off-by: Stefan Eichenberger Reviewed-by: Alan Stern Link: https://lore.kernel.org/r/20250203105840.17539-1-eichest@gmail.com Signed-off-by: Greg Kroah-Hartman

usb: fix reference leak in usb_new_device()

2025-01-17T12:36:22+00:00

commit 0df11fa8cee5a9cf8753d4e2672bb3667138c652 upstream. When device_add(&udev->dev) succeeds and a later call fails, usb_new_device() does not properly call device_del(). As comment of device_add() says, 'if device_add() succeeds, you should call device_del() when you want to get rid of it. If device_add() has not succeeded, use only put_device() to drop the reference count'. Found by code review. Cc: stable Fixes: 9f8b17e643fe ("USB: make usbdevices export their device nodes instead of using a separate class") Signed-off-by: Ma Ke Reviewed-by: Alan Stern Link: https://lore.kernel.org/r/20241218071346.2973980-1-make_ruc2021@163.com Signed-off-by: Greg Kroah-Hartman

usb: Fix regression caused by invalid ep0 maxpacket in virtual SuperSpeed device

2024-05-17T10:02:28+00:00

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 Reported-and-tested-by: Roger Whittaker 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