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Use "ep0in" and "ep0out" instead "ep1in" and "ep0out" which is confusing
and not consistent with the remaining output.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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We already give requests back in dwc3_ep0_stall_and_restart() so
doing it again here will most likely corrupt the list.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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The way it was before was really meaningless.
Now it looks saner.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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We don't need to care about direction on a two stage
transfer.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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According to USB 3.0 Specification, a SetAddress()
while device is in Configured State has an unspecified
behavior (see Section 9.4.6). Still USB30CV wasn't
happy with my Stall reply.
To make that thing happy, just accept the SetAddress()
always. No problems have been observed thus far.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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My webcam is a Logitech C300 and I get "chipmunk"ed squeaky sound.
The following trivial patch fixes it.
Signed-off-by: Jon Levell <linuxusb@coralbark.net>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Add to the dev_state and alloc_async structures the user namespace
corresponding to the uid and euid. Pass these to kill_pid_info_as_uid(),
which can then implement a proper, user-namespace-aware uid check.
Changelog:
Sep 20: Per Oleg's suggestion: Instead of caching and passing user namespace,
uid, and euid each separately, pass a struct cred.
Sep 26: Address Alan Stern's comments: don't define a struct cred at
usbdev_open(), and take and put a cred at async_completed() to
ensure it lasts for the duration of kill_pid_info_as_cred().
Signed-off-by: Serge Hallyn <serge.hallyn@canonical.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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"length" is type size_t so the cast to unsigned int truncates the
upper bytes. This isn't an issue in real life (I've checked the
callers) but it's a bit messy.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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add device ID for "HP un2430 Mobile Broadband Module"
Signed-off-by: Rigbert Hamisch <rigbert@gmx.de>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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In the usb printer class specific request get_device_id the value of
wIndex is (interface << 8 | altsetting) instead of just interface.
This enables the detection of some printers with libusb.
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Matthias Dellweg <2500@gmx.de>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Alan Stern points out that after spin_unlock(&ps->lock) there is no
guarantee that ps->pid won't be freed. Since kill_pid_info_as_uid() is
called after the spin_unlock(), the pid passed to it must be pinned.
Reported-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Serge Hallyn <serge.hallyn@canonical.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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This patch (as1488) improves the comments and logic in uhci-hcd's
suspend routine. The existing comments are hard to understand and
don't give a good idea of what's really going on.
The question of whether EGSM (Enter Global Suspend Mode) and RD
(enable Resume Detect interrupts) can be useful when they're not both
set is difficult. The spec doesn't give any details on how they
interact with system wakeup, although clearly they are meant to be
used together. To be safe, the patch changes the subroutine so that
neither bit gets set unless they both do. There shouldn't be any
functional changes from this; only systems that are designed badly or
broken in some way need to avoid using those bits.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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This patch (as1486) implements the kernel's new wakeup policy for USB
host controllers. Since they don't generate wakeup requests on their
but merely forward requests from their root hubs toward the CPU, they
should be enabled for wakeup by default.
Also, to be compliant with both the old and new policies, root hubs
should not be enabled for remote wakeup by default. Userspace must
enable it explicitly if it is desired.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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This removes the need of ifdefs within the init function and with it the
headache about the correct clean without bus X but with bus/platform Y &
Z.
xhci-pci is only compiled if CONFIG_PCI is selected which can be
de-selected now without trouble. For now the result is kinda useless
because we have no other glue code. However, since nobody is using
USB_ARCH_HAS_XHCI then it should not be an issue :)
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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xhci_gen_setup() is generic so it can be used to perform the bare xhci
setup even on non-pci based platform. The typedef for the function
pointer is moved into the headerfile
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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xhci_pci_setup() is split into three pieces:
- xhci_gen_setup()
The major remaining of xhci_pci_setup() is now containing the generic
part of the xhci setup. It allocates the xhci struct, setup
hcs_params? and friends, performs xhci_halt(), xhci_init and so one.
It also obtains the quirks via a callback
- xhci_pci_quirks()
It checks the origin of the xhci core and sets core specific quirks.
- xhci_pci_setup()
PCI specific setup functions. Besides calling xhci_gen_setup() with
xhci_pci_quirks() as an argument it performs PCI specific setup like
obtaining the address of sbrn via a PCI config space.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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pci_*_consistent() calls dma_*_coherent() with GFP_ATOMIC and requires
pci_dev struct. This is a preparion for later where we no longer have
the pci struct around.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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The MSI related fuctionality requires a few structs which are not
available if CONFIG_PCI is not enabled. This is a prepartion to allow
xhci be built without CONFIG_PCI set.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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This patch moves the complete MSI/MSI-X/Legacy dance into its own
function. There is however one difference: If the XHCI_BROKEN_MSI flag
is set then we don't free and register the irq, we simply return.
This is preparation for later PCI decouple.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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to make it look like OHCI and EHCI, we introduce
that symbol and USB_XHCI_HCD depend on that
instead of PCI.
[bigeasy@linutronix.de: wire up USB_ARCH_HAS_HCD]
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Fix the debug message in xhci_address_device().
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Setting the chain (CH) bit in the link TRB of isochronous transfer rings
is required by AMD 0.96 xHCI host controller to successfully transverse
multi-TRB TD that span through different memory segments.
When a Missed Service Error event occurs, if the chain bit is not set in
the link TRB and the host skips TDs which just across a link TRB, the
host may falsely recognize the link TRB as a normal TRB. You can see
this may cause big trouble - the host does not jump to the right address
which is pointed by the link TRB, but continue fetching the memory which
is after the link TRB address, which may not even belong to the host,
and the result cannot be predicted.
This causes some big problems. Without the former patch I sent: "xHCI:
prevent infinite loop when processing MSE event", the system may hang.
With that patch applied, system does not hang, but the host still access
wrong memory address and isoc transfer will fail. With this patch,
isochronous transfer works as expected.
This patch should be applied to kernels as old as 2.6.36, which was when
the first isochronous support was added for the xHCI host controller.
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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This patch adds sysfs support to xHCI usb2 hardware LPM, so developer can
enable and disable usb2 hardware LPM manually for test purpose.
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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If the device pass the USB2 software LPM and the host supports hardware
LPM, enable hardware LPM for the device to let the host decide when to
put the link into lower power state.
If hardware LPM is enabled for a port and driver wants to put it into
suspend, it must first disable hardware LPM, resume the port into U0,
and then suspend the port.
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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This patch tests USB2 software LPM for a USB2 LPM-capable device.
When a lpm-capable device is addressed, if the host also supports software
LPM, apply a test by putting the device into L1 state and resume it to see
if the device can do L1 suspend/resume successfully.
If the device fails to enter L1 or resume from L1 state, it may not
function normally and usbcore may disconnect and re-enumerate it. In this
case, store the device's Vid and Pid information, make sure the host will
not test LPM for it twice.
The test result is per device/host. Some devices claim to be lpm-capable,
but fail to enter L1 or resume. So the test is necessary.
The xHCI 1.0 errata has modified the USB2.0 LPM implementation. It redefines
the HIRD field to BESL, and adds another register Port Hardware LPM Control
(PORTHLPMC). However, this should not affect the LPM behavior on xHC which
does not implement 1.0 errata.
USB2.0 LPM errata defines a new bit BESL in the device's USB 2.0 extension
descriptor. If the device reports it uses BESL, driver should use BESL
instead of HIRD for it.
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Check the host's USB2 LPM capability.
USB2 software LPM support is optional for xHCI 0.96 hosts. xHCI 1.0 hosts
should support software LPM, and may support hardware LPM.
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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When the link state changes, xHC will report a port status change event
and set the PORT_PLC bit, for both USB3 and USB2 root hub ports.
The PLC will be cleared by usbcore for USB3 root hub ports, but not for
USB2 ports, because they do not report USB_PORT_STAT_C_LINK_STATE in
wPortChange.
Clear it for USB2 root hub ports in handle_port_status().
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Introduce xhci_test_and_clear_bit() to clear RWC bit in PORTSC register.
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Introduce xhci_set_link_state() to remove redundant codes.
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Check device's LPM capability by examining the bmAttibutes field of the
USB2.0 Extension Descriptor.
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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This commit gets BOS(Binary Device Object Store) descriptor set for Super
Speed devices and High Speed devices which support BOS descriptor.
BOS descriptor is used to report additional USB device-level capabilities
that are not reported via the Device descriptor. By getting BOS descriptor
set, driver can check device's device-level capability such as LPM
capability.
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Signed-off-by: Shaun Silk <g0del@bigpond.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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This allow to clean duplicated code in most of SOC driver.
Signed-off-by: Matthieu CASTET <castet.matthieu@free.fr>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org> # fixes 3.1 build error
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Report the number of dropped packets instead of zero
when using the binary usbmon interface with tcpdump.
# tcpdump -i usbmon1 -w dump
tcpdump: listening on usbmon1, link-type USB_LINUX_MMAPPED (USB with padded Linux header), capture size 65535 bytes
^C2155 packets captured
2155 packets received by filter
1019 packets dropped by kernel
Signed-off-by: Johannes Stezenbach <js@sig21.net>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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We should not be using dev_get_drvdata() because we
never call dev_set_drvdata(). Let's use container_of()
as all other sysfs attributes.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Add vendor and product ID for the SMART USB to serial adapter. These
were meant to be used with their SMART Board whiteboards, but can be
re-purposed for other tasks. Tested and working (at at least 9600 bps).
Signed-off-by: Eric Benoit <eric@ecks.ca>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Simple patch to make qcserial recognize the USB id of the Sierra
Wireless MC8355 which is based on the Gobi 3000 chip.
Both UMTS and GPS work fine.
Signed-off-by: Richard Hartmann <richih.mailinglist@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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The seg argument to xhci_segment_free is never passed as NULL, so
no need to check for this in xhci_segment_free.
Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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There are 2 situations wherein the xhci_ring* might not get freed:
- When xhci_ring_alloc() -> xhci_segment_alloc() returns NULL and
we goto the fail: label in xhci_ring_alloc. In this case, the ring
will not get kfreed.
- When the num_segs argument to xhci_ring_alloc is passed as 0 and
we try to free the rung after that.
( This doesn't really happen as of now in the code but we seem to
be entertaining num_segs=0 in xhci_ring_alloc )
This should be backported to kernels as old as 2.6.31.
Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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When a hot reset (standard USB port reset) fails on a USB 3.0 port, the
host controller transitions to the "Error" state. It reports the port
link state as "Inactive", sets the link state change flag, and (if the
device disconnects) also reports the disconnect and connect change status.
It's also supposed to transition the link state to "RxDetect", but the NEC
µPD720200 xHCI host does not.
Unfortunately, Harald found that the combination of the NEC µPD720200 and
a LogiLink USB 3.0 to SATA adapter triggered this issue. The USB core
would reset the device, the port would go into this error state, and the
device would never be enumerated. This combination works under Windows,
but not under Linux.
When a hot reset fails on a USB 3.0 port, and the link state is reported
as Inactive, fall back to a warm port reset instead. Harald confirms that
with a warm port reset (along with all the change bits being correctly
cleared), the USB 3.0 device will successfully enumerate.
Harald also had to add two other patches ("xhci: Set change bit when warm
reset change is set." and "usbcore: refine warm reset logic") to make this
setup work. Since the warm reset refinement patch is not destined for the
stable kernels (it's too big), this patch should not be backported either.
This fixes https://bugzilla.kernel.org/show_bug.cgi?id=41752
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: Harald Brennich <harald.brennich@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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The Intel Panther Point xHCI host tracks SuperSpeed endpoints in a
different way than USB 2.0/1.1 endpoints. The bandwidth interval tables
are not used, and instead the bandwidth is calculated in a very simple
way. Bandwidth for SuperSpeed endpoints is tracked individually in each
direction, since each direction has the full USB 3.0 bandwidth available.
10% of the bus bandwidth is reserved for non-periodic transfers.
This checking would be more complex if we had USB 3.0 LPM enabled, because
an additional latency for isochronous ping times need to be taken into
account. However, we don't have USB 3.0 LPM support in Linux yet.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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The "Mult" bits in the SuperSpeed Endpoint Companion Descriptor are
zero-based, and the xHCI host controller wants them to be zero-based in
the input context. However, for the bandwidth math, we want them to be
one-based. Fix this.
Fix the documentation about the endpoint bandwidth mult variable in the
xhci.h file, which says it is zero-based. Also fix the documentation
about num_packets, which is also one-based, not zero-based.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Current waiting time for warm(BH) reset in hub_port_warm_reset() is too short
for xHC host to complete the warm reset and report a BH reset change.
This patch increases the waiting time for warm reset and merges the function
into hub_port_reset(), so it can handle both cold reset and warm reset, and
factor out hub_port_finish_reset() to make the code looks cleaner.
This fixes the issue that driver fails to clear BH reset change and port is
"dead".
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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instead of reading the xhci interface version each time _even_ if the
quirk is not required, simply check if the quirk flag is set. This flag
is only set of the module parameter is set and here is where I moved the
version check to.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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After auto-delink command is triggered, the CSW won't be sent back
to host side, in which scenario, the USB Mass Storage driver will
wait for the completion of the URB for MAX_SCHEDULE_TIMEOUT.
Signed-off-by: edwin_rong <edwin_rong@realsil.com.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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The new runtime PM code has shown that many webcams suffer
from a race condition that may crash them upon resume.
Runtime PM is especially prone to show the problem because
it retains power to the cameras at all times. However
system suspension may also crash the devices and retain
power to the devices.
The only way to solve this problem without races is in
usbcore with the RESET_RESUME quirk.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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This patch (as1484) adds documentation for ehci-hcd's "companion"
sysfs attribute, which was added to the kernel over four years ago but
never documented.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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* 'for-next' of git://gitorious.org/usb/usb: (47 commits)
usb: musb: Enable DMA mode1 RX for transfers without short packets
usb: musb: fix build breakage
usb: gadget: audio: queue wLength-sized requests
usb: gadget: audio: actually support both speeds
usb: gadget: storage: make FSG_NUM_BUFFERS variable size
USB: gadget: storage: remove alignment assumption
usb: gadget: storage: adapt logic block size to bound block devices
usb: dwc3: gadget: improve debug on link state change
usb: dwc3: omap: set idle and standby modes
usb: dwc3: ep0: introduce ep0_expect_in flag
usb: dwc3: ep0: giveback requests on stall_and_restart
usb: dwc3: gadget: drop the useless dma_sync_single* calls
usb: dwc3: gadget: fix GCTL programming
usb: dwc3: define ScaleDown macro helper
usb: dwc3: Fix definition of DWC3_GCTL_U2RSTECN
usb: dwc3: gadget: do not map/unmap ZLP transfers
usb: dwc3: omap: fix IRQ handling
usb: dwc3: omap: change IRQ name to dwc3-omap
usb: dwc3: add module.h to dwc3-omap.c and core.c
usb: dwc3: omap: distinguish between SW and HW modes
...
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This flag is a NOOP and can be removed now.
Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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According to ehci spec 4.10.2, Advance Queue
If the fetched qTD has its Active bit set to a zero, the
host controller aborts the queue advance and follows the
queue head's horizontal pointer to the next schedule data
structure.
the 'qtd' will be linked into qh hardware queue after the line
below
*dummy = *qtd;
is executed and observed by EHCI HC, but EHCI HC won't have chance to
fetch the qtd descriptor pointed by 'qtd' in qh_append_tds until the
line below
dummy->hw_token = token; #set Active bit here
is executed by CPU and observed by EHCI HC.
There is already one 'wmb' to order writing to 'dummy'/'qtd' descriptors
and writing 'token' to 'dummy' descriptor(set Active bit), so the 1st
wmb is not needed and can be removed.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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