26 Aug, 2015
1 commit
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After the recent fix of runtime PM for USB-audio driver, we got a
lockdep warning like:=============================================
[ INFO: possible recursive locking detected ]
4.2.0-rc8+ #61 Not tainted
---------------------------------------------
pulseaudio/980 is trying to acquire lock:
(&chip->shutdown_rwsem){.+.+.+}, at: [] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio]
but task is already holding lock:
(&chip->shutdown_rwsem){.+.+.+}, at: [] snd_usb_autoresume+0x1d/0x52 [snd_usb_audio]This comes from snd_usb_autoresume() invoking down_read() and it's
used in a nested way. Although it's basically safe, per se (as these
are read locks), it's better to reduce such spurious warnings.The read lock is needed to guarantee the execution of "shutdown"
(cleanup at disconnection) task after all concurrent tasks are
finished. This can be implemented in another better way.Also, the current check of chip->in_pm isn't good enough for
protecting the racy execution of multiple auto-resumes.This patch rewrites the logic of snd_usb_autoresume() & co; namely,
- The recursive call of autopm is avoided by the new refcount,
chip->active. The chip->in_pm flag is removed accordingly.
- Instead of rwsem, another refcount, chip->usage_count, is introduced
for tracking the period to delay the shutdown procedure. At
the last clear of this refcount, wake_up() to the shutdown waiter is
called.
- The shutdown flag is replaced with shutdown atomic count; this is
for reducing the lock.
- Two new helpers are introduced to simplify the management of these
refcounts; snd_usb_lock_shutdown() increases the usage_count, checks
the shutdown state, and does autoresume. snd_usb_unlock_shutdown()
does the opposite. Most of mixer and other codes just need this,
and simply returns an error if it receives an error from lock.Fixes: 9003ebb13f61 ('ALSA: usb-audio: Fix runtime PM unbalance')
Reported-and-tested-by: Alexnader Kuleshov
Signed-off-by: Takashi Iwai
17 May, 2013
1 commit
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freqshift is only set for the data endpoint and syncmaxsize is only set
for the sync endpoint. This results in a syncmaxsize of zero used in the
proc output feedback format calculation, which gives a feedback format
incorrectly shown as 8.16 for UAC2 devices.As neither the data nor the sync endpoint gives all the relevant
content, output the two combined.Also remove the sync_endpoint "packet size" which is always zero
and the sync_endpoint "momentary freq" which is constant.Tested with UAC2 async and UAC1 adaptive, not tested with UAC1 async.
Reported-by: B. Zhang
Signed-off-by: Torstein Hegge
Signed-off-by: Takashi Iwai
29 Apr, 2013
1 commit
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Add a function to handle conversion from snd_pcm_format_t
to bitwise with proper typing.Change such conversions to use this function and silence sparse
warnings.Signed-off-by: Eldad Zack
Signed-off-by: Takashi Iwai
04 Apr, 2013
1 commit
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Change occurances of list_for_each into list_for_each_entry where
applicable.Signed-off-by: Eldad Zack
Signed-off-by: Takashi Iwai
30 Oct, 2012
1 commit
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Close some races at disconnection of a USB audio device by adding the
chip->shutdown_mutex and chip->shutdown check at appropriate places.The spots to put bandaids are:
- PCM prepare, hw_params and hw_free
- where the usb device is accessed for communication or get speed, in
mixer.c and others; the device speed is now cached in subs->speed
instead of accessing to chip->devThe accesses in PCM open and close don't need the mutex protection
because these are already handled in the core PCM disconnection code.The autosuspend/autoresume codes are still uncovered by this patch
because of possible mutex deadlocks. They'll be covered by the
upcoming change to rwsem.Also the mixer codes are untouched, too. These will be fixed in
another patch, too.Reported-by: Matthieu CASTET
Cc:
Signed-off-by: Takashi Iwai
21 Apr, 2012
1 commit
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Drop some struct members and definitions that became obsolete during
the refactorization of the driver.Signed-off-by: Daniel Mack
Signed-off-by: Takashi Iwai
13 Apr, 2012
1 commit
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Many fields have been moved to struct snd_usb_endpoint.
Also fix the proc output to correspond to the new structure.Signed-off-by: Takashi Iwai
27 Oct, 2010
1 commit
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There are two USB Audio Class specifications (v1 and v2), but neither of
them clearly defines the feedback format for high-speed UAC v1 devices.
Add to this whatever the Creative and M-Audio firmware writers have been
smoking, and it becomes impossible to predict the exact feedback format
used by a particular device.Therefore, automatically detect the feedback format by looking at the
magnitude of the first received feedback value.Also, this allows us to get rid of some special cases for E-Mu devices.
Signed-off-by: Clemens Ladisch
Signed-off-by: Takashi Iwai
14 Aug, 2010
1 commit
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This is V2 of the patch, after feedback from Clemens and Daniel.
This patch adds SuperSpeed support to the USB drivers under sound/. It adds
tests for USB_SPEED_SUPER to the appropriate places that check for the USB
speed.This patch has been tested with our SS USB3 device emulating a set of Yamaha
speakers and a Logitech microphone, but with the descriptors modified to add
USB3 support. It has also been tested with the real speakers and microphone,
to make sure that USB2 devices still work.Signed-off-by: Paul Zimmerman
Cc: Clemens Ladisch
Cc: Daniel Mack
Cc: Greg Kroah-Hartman
Signed-off-by: Takashi Iwai
05 Mar, 2010
3 commits
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In preparation for USB audio 2.0 support, change the audioformat
structure so that it uses a bitmask to specify possible formats.Signed-off-by: Clemens Ladisch
Signed-off-by: Takashi Iwai -
The snd_usb_substream::format field actually contains the index of the
current alternate setting, so rename it to altset_idx to avoid
confusion.Signed-off-by: Clemens Ladisch
Signed-off-by: Takashi Iwai -
Clean up the usb audio driver by factoring out a lot of functions to
separate files. Code for procfs, quirks, urbs, format parsers etc all
got a new home now.Moved almost all special quirk handling to quirks.c and introduced new
generic functions to handle them, so the exceptions do not pollute the
whole driver.Renamed usbaudio.c to card.c because this is what it actually does now.
Renamed usbmidi.c to midi.c for namespace clarity.
Removed more things from usbaudio.h.The non-standard drivers were adopted accordingly.
Signed-off-by: Daniel Mack
Cc: Clemens Ladisch
Signed-off-by: Takashi Iwai
