usb: gadget: u_audio: Use C99 syntax for array initializers

Convert array initializers to C99 syntax by adding the '=' after
each designated initializer.

Fix the following smatch warnings:

drivers

usb: gadget: u_audio: Use C99 syntax for array initializers

Convert array initializers to C99 syntax by adding the '=' after
each designated initializer.

Fix the following smatch warnings:

drivers/usb/gadget/function/u_audio.c:1117:20:
warning: obsolete array initializer, use C99 syntax
drivers/usb/gadget/function/u_audio.c:1124:28:
warning: obsolete array initializer, use C99 syntax
drivers/usb/gadget/function/u_audio.c:1131:19:
warning: obsolete array initializer, use C99 syntax
drivers/usb/gadget/function/u_audio.c:1138:27:
warning: obsolete array initializer, use C99 syntax
drivers/usb/gadget/function/u_audio.c:1145:25:
warning: obsolete array initializer, use C99 syntax

Also, fix two checkpatch.pl warnings:

WARNING: please, no spaces at the start of a line
+ [UAC_FBACK_CTRL] = {$

WARNING: please, no spaces at the start of a line
+ [UAC_MUTE_CTRL] = {$

Signed-off-by: Abhishek Tamboli <[email protected]>
Reviewed-by: Ricardo B. Marliere <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

usb: gadget: u_audio: Check return codes from usb_ep_enable and config_ep_by_speed.

These functions can fail if descriptors are malformed, or missing,
for the selected USB speed.

Fixes: eb9fecb9e69

usb: gadget: u_audio: Check return codes from usb_ep_enable and config_ep_by_speed.

These functions can fail if descriptors are malformed, or missing,
for the selected USB speed.

Fixes: eb9fecb9e69b ("usb: gadget: f_uac2: split out audio core")
Fixes: 24f779dac8f3 ("usb: gadget: f_uac2/u_audio: add feedback endpoint support")
Cc: [email protected]
Signed-off-by: Chris Wulff <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

usb: gadget: u_audio: Clear uac pointer when freed.

This prevents use of a stale pointer if functions are called after
g_cleanup that shouldn't be. This doesn't fix any races, but converts
a possibl

usb: gadget: u_audio: Clear uac pointer when freed.

This prevents use of a stale pointer if functions are called after
g_cleanup that shouldn't be. This doesn't fix any races, but converts
a possibly silent kernel memory corruption into an obvious NULL pointer
dereference report.

Fixes: eb9fecb9e69b ("usb: gadget: f_uac2: split out audio core")
Signed-off-by: Chris Wulff <[email protected]>
Link: https://lore.kernel.org/stable/CO1PR17MB54194226DA08BFC9EBD8C163E1172%40CO1PR17MB5419.namprd17.prod.outlook.com
Link: https://lore.kernel.org/r/CO1PR17MB54194226DA08BFC9EBD8C163E1172@CO1PR17MB5419.namprd17.prod.outlook.com
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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usb: gadget: u_audio: Fix race condition use of controls after free during gadget unbind.

Hang on to the control IDs instead of pointers since those are correctly
handled with locks.

Fixes: 8fe9a03

usb: gadget: u_audio: Fix race condition use of controls after free during gadget unbind.

Hang on to the control IDs instead of pointers since those are correctly
handled with locks.

Fixes: 8fe9a03f4331 ("usb: gadget: u_audio: Rate ctl notifies about current srate (0=stopped)")
Fixes: c565ad07ef35 ("usb: gadget: u_audio: Support multiple sampling rates")
Fixes: 02de698ca812 ("usb: gadget: u_audio: add bi-directional volume and mute support")
Signed-off-by: Chris Wulff <[email protected]>
Link: https://lore.kernel.org/stable/CO1PR17MB5419C2BF44D400E4E620C1ADE1172%40CO1PR17MB5419.namprd17.prod.outlook.com
Link: https://lore.kernel.org/r/CO1PR17MB5419C2BF44D400E4E620C1ADE1172@CO1PR17MB5419.namprd17.prod.outlook.com
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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usb: gadget: u_audio: Use snprintf() instead of sprintf()

In order to be consistent with other s[n]printf() usage in this file,
switch to snprintf() here as well.

Signed-off-by: Christophe JAILLET

usb: gadget: u_audio: Use snprintf() instead of sprintf()

In order to be consistent with other s[n]printf() usage in this file,
switch to snprintf() here as well.

Signed-off-by: Christophe JAILLET <[email protected]>
Link: https://lore.kernel.org/r/5703e697687e4a39059bf90659969ffc86b2cfbd.1711176701.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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usb: gadget: u_audio: Use the 2-argument version of strscpy()

In order to be consistent with other strscpy() usage in this file and less
verbose, use the new 2-argument version of strscpy() which co

usb: gadget: u_audio: Use the 2-argument version of strscpy()

In order to be consistent with other strscpy() usage in this file and less
verbose, use the new 2-argument version of strscpy() which computes
auto-magically the size of the destination.

Signed-off-by: Christophe JAILLET <[email protected]>
Link: https://lore.kernel.org/r/e7fd0ec5a8b37799271c6d74c325cfb980d44181.1711176701.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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usb: gadget: u_audio: Fix the size of a buffer in a strscpy() call

The size given to strscpy() is not consistent with the destination buffer
that is used. The size is related to 'driver' and the buf

usb: gadget: u_audio: Fix the size of a buffer in a strscpy() call

The size given to strscpy() is not consistent with the destination buffer
that is used. The size is related to 'driver' and the buffer is
'mixername'.

sizeof(card->mixername) is 80 and sizeof(card->driver) is 16, so in
theory this could lead to unneeded string truncation.

In practice, this is not the case because g_audio_setup() has only 2
callers. 'card_name' is either "UAC1_Gadget" or "UAC2_Gadget".

Anyway, using the correct size is cleaner and more future proof.

In order to be less verbose, use the new 2-argument version of strscpy()
which computes auto-magically the size of the destination.

Signed-off-by: Christophe JAILLET <[email protected]>
Link: https://lore.kernel.org/r/bf8a9353319566624f653531b80e5caf3d346ba1.1711176700.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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usb: gadget: u_audio: don't let userspace block driver unbind

In the unbind callback for f_uac1 and f_uac2, a call to snd_card_free()
via g_audio_cleanup() will disconnect the card and then wait for

usb: gadget: u_audio: don't let userspace block driver unbind

In the unbind callback for f_uac1 and f_uac2, a call to snd_card_free()
via g_audio_cleanup() will disconnect the card and then wait for all
resources to be released, which happens when the refcount falls to zero.
Since userspace can keep the refcount incremented by not closing the
relevant file descriptor, the call to unbind may block indefinitely.
This can cause a deadlock during reboot, as evidenced by the following
blocked task observed on my machine:

task:reboot state:D stack:0 pid:2827 ppid:569 flags:0x0000000c
Call trace:
__switch_to+0xc8/0x140
__schedule+0x2f0/0x7c0
schedule+0x60/0xd0
schedule_timeout+0x180/0x1d4
wait_for_completion+0x78/0x180
snd_card_free+0x90/0xa0
g_audio_cleanup+0x2c/0x64
afunc_unbind+0x28/0x60
...
kernel_restart+0x4c/0xac
__do_sys_reboot+0xcc/0x1ec
__arm64_sys_reboot+0x28/0x30
invoke_syscall+0x4c/0x110
...

The issue can also be observed by opening the card with arecord and
then stopping the process through the shell before unbinding:

# arecord -D hw:UAC2Gadget -f S32_LE -c 2 -r 48000 /dev/null
Recording WAVE '/dev/null' : Signed 32 bit Little Endian, Rate 48000 Hz, Stereo
^Z[1]+ Stopped arecord -D hw:UAC2Gadget -f S32_LE -c 2 -r 48000 /dev/null
# echo gadget.0 > /sys/bus/gadget/drivers/configfs-gadget/unbind
(observe that the unbind command never finishes)

Fix the problem by using snd_card_free_when_closed() instead, which will
still disconnect the card as desired, but defer the task of freeing the
resources to the core once userspace closes its file descriptor.

Fixes: 132fcb460839 ("usb: gadget: Add Audio Class 2.0 Driver")
Cc: [email protected]
Signed-off-by: Alvin Šipraga <[email protected]>
Reviewed-by: Ruslan Bilovol <[email protected]>
Reviewed-by: John Keeping <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

usb: gadget: u_audio: clean up some inconsistent indenting

Eliminate the follow smatch warning:

drivers/usb/gadget/function/u_audio.c:1182 g_audio_setup() warn:
inconsistent indenting.

Reported-by

usb: gadget: u_audio: clean up some inconsistent indenting

Eliminate the follow smatch warning:

drivers/usb/gadget/function/u_audio.c:1182 g_audio_setup() warn:
inconsistent indenting.

Reported-by: Abaci Robot <[email protected]>
Signed-off-by: Jiapeng Chong <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

usb: gadget: u_audio: Add suspend call

Add exported method u_audio_suspend which sets stream status to
inactive and sends notifications. The method does not free any
resources.

Signed-off-by: Pavel

usb: gadget: u_audio: Add suspend call

Add exported method u_audio_suspend which sets stream status to
inactive and sends notifications. The method does not free any
resources.

Signed-off-by: Pavel Hofman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

usb: gadget: u_audio: Rate ctl notifies about current srate (0=stopped)

The Playback/Capture ctl currently reports rate value set by USB
control selector UAC2_CS_CONTROL_SAM_FREQ (fixed for UAC1). W

usb: gadget: u_audio: Rate ctl notifies about current srate (0=stopped)

The Playback/Capture ctl currently reports rate value set by USB
control selector UAC2_CS_CONTROL_SAM_FREQ (fixed for UAC1). When the
stops playback/capture, the reported value does not change. The gadget
side has no information whether the host has started/stopped
capture/playback.

This patch sets the value reported by the respective rate ctl to zero
when the host side has stopped playback/capture. Also, it calls
snd_ctl_notify when start/stop occurs, so that a subscribed client can
act appropriately.

Tests have confirmed that USB hosts change UAC2_CS_CONTROL_SAM_FREQ
before switching altsetting to activate playback/capture, resulting in
correct order (params->c/p_srate is set to requested rate before
u_audio_start_capture/playback is called).

The gadget rate notifications are used by user-space audio gadget
controller gaudio_ctl https://github.com/pavhofman/gaudio_ctl.

Signed-off-by: Pavel Hofman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

usb: gadget: u_audio: Add capture/playback srate getter

UAC1/UAC2 functions will need to query u_audio about the currently set
srate. Add the getter functions.

Signed-off-by: Pavel Hofman <pavel.ho

usb: gadget: u_audio: Add capture/playback srate getter

UAC1/UAC2 functions will need to query u_audio about the currently set
srate. Add the getter functions.

Signed-off-by: Pavel Hofman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

usb: gadget: u_audio: Move dynamic srate from params to rtd

Parameters uac_params.p_srate/c_srate are dynamic now and are not part
of parametric configuration anymore. Move them to the
runtime struc

usb: gadget: u_audio: Move dynamic srate from params to rtd

Parameters uac_params.p_srate/c_srate are dynamic now and are not part
of parametric configuration anymore. Move them to the
runtime struct uac_rtd_params for each stream.

Suggested-by: John Keeping <[email protected]>
Signed-off-by: Pavel Hofman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

usb: gadget: u_audio: Support multiple sampling rates

Implement support for multiple sampling rates in u_audio part of the
audio gadget. The currently configured rates are exposed through
read-only

usb: gadget: u_audio: Support multiple sampling rates

Implement support for multiple sampling rates in u_audio part of the
audio gadget. The currently configured rates are exposed through
read-only amixer controls 'Capture Rate' and 'Playback Rate'.

Signed-off-by: Julian Scheel <[email protected]>
Signed-off-by: Pavel Hofman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

usb: gadget: u_audio: Subdevice 0 for capture ctls

Both capture and playback alsa devices use subdevice 0. Yet capture-side
ctls are defined for subdevice 1. The patch sets subdevice 0 for them.

Fi

usb: gadget: u_audio: Subdevice 0 for capture ctls

Both capture and playback alsa devices use subdevice 0. Yet capture-side
ctls are defined for subdevice 1. The patch sets subdevice 0 for them.

Fixes: 02de698ca812 ("usb: gadget: u_audio: add bi-directional volume and mute support")
Signed-off-by: Pavel Hofman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

usb: gadget: u_audio: fix calculations for small bInterval

If bInterval is 1, then p_interval is 8000 and p_interval_mil is 8E9,
which is too big for a 32-bit value. While the storage is indeed
64-

usb: gadget: u_audio: fix calculations for small bInterval

If bInterval is 1, then p_interval is 8000 and p_interval_mil is 8E9,
which is too big for a 32-bit value. While the storage is indeed
64-bit, this value is used as the divisor in do_div() which will
truncate it into a uint32_t leading to incorrect calculated values.

Switch back to keeping the base value in struct snd_uac_chip which fits
easily into an int, meaning that the division can be done in two steps
with the divisor fitting safely into a uint32_t on both steps.

Fixes: 6fec018a7e70 ("usb: gadget: u_audio.c: Adding Playback Pitch ctl for sync playback")
Tested-by: Pavel Hofman <[email protected]>
Signed-off-by: John Keeping <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

usb: gadget: u_audio.c: Adding Playback Pitch ctl for sync playback

EP IN is hard-coded as ASYNC both in f_uac1 and f_uac2 but u_audio sends
steady number of audio frames in each USB packet, without

usb: gadget: u_audio.c: Adding Playback Pitch ctl for sync playback

EP IN is hard-coded as ASYNC both in f_uac1 and f_uac2 but u_audio sends
steady number of audio frames in each USB packet, without any control.

This patch adds 'Playback Pitch 1000000' ctl analogous to the existing
'Capture Pitch 1000000' ctl. The calculation of playback req->length in
u_audio_iso_complete respects the Playback Pitch ctl value to 1ppm now.

Max. value for Playback Pitch is configured by the existing parameter
uac2_opts->fb_max, used also for the Capture Pitch.

Since the EP IN packet size can be increased by uac2_opts->fb_max now,
maxPacketSize for the playback direction is calculated by the same
algorithm as for the async capture direction in
f_uac2.c:set_ep_max_packet_size.

Signed-off-by: Pavel Hofman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

usb: gadget: u_audio: EP-OUT bInterval in fback frequency

The patch increases the bitshift in feedback frequency
calculation with EP-OUT bInterval value.

Tests have revealed that Win10 and OSX UAC2

usb: gadget: u_audio: EP-OUT bInterval in fback frequency

The patch increases the bitshift in feedback frequency
calculation with EP-OUT bInterval value.

Tests have revealed that Win10 and OSX UAC2 drivers require
the feedback frequency to be based on the actual packet
interval instead of on the USB2 microframe. Otherwise they
ignore the feedback value. Linux snd-usb-audio driver
detects the applied bitshift automatically.

Tested-by: Henrik Enquist <[email protected]>
Signed-off-by: Pavel Hofman <[email protected]>
Cc: stable <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

usb: gadget: u_audio: fix race condition on endpoint stop

If the endpoint completion callback is call right after the ep_enabled flag
is cleared and before usb_ep_dequeue() is call, we could do a do

usb: gadget: u_audio: fix race condition on endpoint stop

If the endpoint completion callback is call right after the ep_enabled flag
is cleared and before usb_ep_dequeue() is call, we could do a double free
on the request and the associated buffer.

Fix this by clearing ep_enabled after all the endpoint requests have been
dequeued.

Fixes: 7de8681be2cd ("usb: gadget: u_audio: Free requests only after callback")
Cc: stable <[email protected]>
Reported-by: Thinh Nguyen <[email protected]>
Signed-off-by: Jerome Brunet <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

usb: gadget: f_uac2: fixup feedback endpoint stop

When the uac2 function is stopped, there seems to be an issue reported on
some platforms (Intel Merrifield at least)

BUG: kernel NULL pointer deref

usb: gadget: f_uac2: fixup feedback endpoint stop

When the uac2 function is stopped, there seems to be an issue reported on
some platforms (Intel Merrifield at least)

BUG: kernel NULL pointer dereference, address: 0000000000000008
...
RIP: 0010:dwc3_gadget_del_and_unmap_request+0x19/0xe0
...
Call Trace:
dwc3_remove_requests.constprop.0+0x12f/0x170
__dwc3_gadget_ep_disable+0x7a/0x160
dwc3_gadget_ep_disable+0x3d/0xd0
usb_ep_disable+0x1c/0x70
u_audio_stop_capture+0x79/0x120 [u_audio]
afunc_set_alt+0x73/0x80 [usb_f_uac2]
composite_setup+0x224/0x1b90 [libcomposite]

The issue happens only when the gadget is using the sync type "async", not
"adaptive". This indicates that problem is coming from the feedback
endpoint, which is only used with async synchronization mode.

The problem is that request is freed regardless of usb_ep_dequeue(), which
ends up badly if the request is not actually dequeued yet.

Update the feedback endpoint free function to release the endpoint the same
way it is done for the data endpoint, which takes care of the problem.

Fixes: 24f779dac8f3 ("usb: gadget: f_uac2/u_audio: add feedback endpoint support")
Reported-by: Ferry Toth <[email protected]>
Tested-by: Ferry Toth <[email protected]>
Acked-by: Felipe Balbi <[email protected]>
Signed-off-by: Jerome Brunet <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

usb: gadget: u_audio: add bi-directional volume and mute support

USB Audio Class 1/2 have ability to change device's
volume and mute by USB Host through class-specific control
requests. Device also

usb: gadget: u_audio: add bi-directional volume and mute support

USB Audio Class 1/2 have ability to change device's
volume and mute by USB Host through class-specific control
requests. Device also can notify Host about volume/mute
change on its side through optional interrupt endpoint.

This patch adds Volume and Mute ALSA controls which can be
used by user to send and receive notifications to/from
the USB Host about Volume and Mute change.

These params come from f_uac* so volume and mute controls
will be created only if the function support and enable
each explicitly

Signed-off-by: Ruslan Bilovol <[email protected]>
Signed-off-by: Pavel Hofman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

usb: gadget: u_audio: add real feedback implementation

This adds interface between userspace and feedback endpoint to report real
feedback frequency to the Host.

Current implementation adds new use

usb: gadget: u_audio: add real feedback implementation

This adds interface between userspace and feedback endpoint to report real
feedback frequency to the Host.

Current implementation adds new userspace interface ALSA mixer control
"Capture Pitch 1000000" (similar to aloop driver's "PCM Rate Shift 100000"
mixer control)

Value in PPM is chosen to have correction value agnostic of the actual HW
rate, which the application is not necessarily dealing with, while still
retaining a good enough precision to allow smooth clock correction on the
playback side, if necessary.

Similar to sound/usb/endpoint.c, a slow down is allowed up to 25%. This
has no impact on the required bandwidth. Speedup correction has an impact
on the bandwidth reserved for the isochronous endpoint. The default
allowed speedup is 500ppm. This seems to be more than enough but, if
necessary, this is configurable through a module parameter. The reserved
bandwidth is rounded up to the next packet size.

Usage of this new control is easy to implement in existing userspace tools
like alsaloop from alsa-utils.

Signed-off-by: Ruslan Bilovol <[email protected]>
Signed-off-by: Jerome Brunet <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

usb: gadget: f_uac2/u_audio: add feedback endpoint support

As per USB and UAC2 specs, asynchronous audio sink endpoint
requires explicit synchronization mechanism (Isochronous
Feedback Endpoint)

Im

usb: gadget: f_uac2/u_audio: add feedback endpoint support

As per USB and UAC2 specs, asynchronous audio sink endpoint
requires explicit synchronization mechanism (Isochronous
Feedback Endpoint)

Implement feedback companion endpoint for ISO OUT endpoint

This patch adds all required infrastructure and USB requests
handling for feedback endpoint. Syncrhonization itself is
still dummy (feedback ep always reports 'nomimal frequency'
e.g. no adjustement is needed). This satisfies hosts that
require feedback endpoint (like Win10) and poll it periodically

Actual synchronization mechanism should be implemented
separately

Signed-off-by: Ruslan Bilovol <[email protected]>
Signed-off-by: Jerome Brunet <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

usb: gadget: u_audio: convert to strscpy

Usage of strlcpy in Linux Kernel has been recently
deprecated [1], convert driver to strscpy

[1] https://lore.kernel.org/lkml/CAHk-=wgfRnXz0W3D37d01q3JFkr_i

usb: gadget: u_audio: convert to strscpy

Usage of strlcpy in Linux Kernel has been recently
deprecated [1], convert driver to strscpy

[1] https://lore.kernel.org/lkml/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/

Signed-off-by: Ruslan Bilovol <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

usb: gadget: u_audio: clean up locking

snd_pcm_stream_lock() is held when the ALSA .trigger() callback is called.
The lock of 'struct uac_rtd_params' is not necessary since all its locking
operation

usb: gadget: u_audio: clean up locking

snd_pcm_stream_lock() is held when the ALSA .trigger() callback is called.
The lock of 'struct uac_rtd_params' is not necessary since all its locking
operation are done under the snd_pcm_stream_lock() too.

Also, usb_request .complete() is called with irqs disabled, so saving and
restoring the irqs is not necessary.

Acked-by: Felipe Balbi <[email protected]>
Signed-off-by: Jerome Brunet <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...