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  1. Dec 26, 2022
  3. Dec 22, 2022
  5. Dec 07, 2022
  7. Dec 05, 2022
    • Takashi Iwai's avatar
      ALSA: usb-audio: Workaround for XRUN at prepare · 198dde08
      Takashi Iwai authored 
      
Under certain situations (typically in the implicit feedback mode),
USB-audio driver starts a playback stream already at PCM prepare call
even before the actual PCM trigger-START call.  For implicit feedback
mode, this effectively starts two streams for data and sync
endpoints, and if a coupled sync stream gets XRUN at this point, it
results in an error -EPIPE.

The problem is that currently we return -EPIPE error as is from the
prepare.  Then application tries to recover again via the prepare
call, but it'll fail again because the sync-stop is missing.  The
sync-stop is missing because it's an internal trigger call (hence the
PCM core isn't involved).

Since we'll need to re-issue the prepare in anyway when trapped into
this pitfall, this patch attempts to address it in a bit different
way; namely, the driver tries to prepare once again after syncing the
stop manually by itself -- so applications don't see the internal
error.  At the second failure, we report the error as is, but this
shouldn't happen in normal situations.

Reported-and-tested-by: default avatarCarl Hetherington <lists@carlh.net>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/b4e71631-4a94-613-27b2-fb595792630@carlh.net
Link: https://lore.kernel.org/r/20221205132124.11585-4-tiwai@suse.de


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      198dde08
  9. Nov 29, 2022
    • John Keeping's avatar
      ALSA: usb-audio: Add quirk for Tascam Model 12 · 67df411d
      John Keeping authored and Takashi Iwai's avatar Takashi Iwai committed 
      
Tascam's Model 12 is a mixer which can also operate as a USB audio
interface.  The audio interface uses explicit feedback but it seems that
it does not correctly handle missing isochronous frames.

When injecting an xrun (or doing anything else that pauses the playback
stream) the feedback rate climbs (for example, at 44,100Hz nominal, I
see a stable rate around 44,099 but xrun injection sees this peak at
around 44,135 in most cases) and glitches are heard in the audio stream
for several seconds - this is significantly worse than the single glitch
expected for an underrun.

While the stream does normally recover and the feedback rate returns to
a stable value, I have seen some occurrences where this does not happen
and the rate continues to increase while no audio is heard from the
output.  I have not found a solid reproduction for this.

This misbehaviour can be avoided by totally resetting the stream state
by switching the interface to alt 0 and back before restarting the
playback stream.

Add a new quirk flag which forces the endpoint and interface to be
reconfigured whenever the stream is stopped, and use this for the Tascam
Model 12.

Separate interfaces are used for the playback and capture endpoints, so
resetting the playback interface here will not affect the capture stream
if it is running.  While there are two endpoints on the interface,
these are the OUT data endpoint and the IN explicit feedback endpoint
corresponding to it and these are always stopped and started together.

Signed-off-by: default avatarJohn Keeping <john@metanate.com>
Link: https://lore.kernel.org/r/20221129130100.1257904-1-john@metanate.com


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      67df411d
  11. Nov 12, 2022
  13. Nov 10, 2022
  15. Nov 09, 2022
  17. Nov 08, 2022
  19. Oct 21, 2022
  21. Oct 09, 2022
  23. Sep 30, 2022
  25. Sep 27, 2022
  27. Sep 20, 2022
    • Takashi Iwai's avatar
      ALSA: usb-audio: Properly refcounting clock rate · 9a737e7f
      Takashi Iwai authored 
      We fixed the bug introduced by the patch for managing the shared
clocks at the commit 809f44a0 ("ALSA: usb-audio: Clear fixed clock
rate at closing EP"), but it was merely a workaround.  By this change,
the clock reference rate is cleared at each EP close, hence the still
remaining EP may need a re-setup of rate unnecessarily.

This patch introduces the proper refcounting for the clock reference
object so that the clock setup is done only when needed.

Fixes: 809f44a0 ("ALSA: usb-audio: Clear fixed clock rate at closing EP")
Fixes: c11117b6 ("ALSA: usb-audio: Refcount multiple accesses on the single clock")
Link: https://lore.kernel.org/r/20220920181126.4912-1-tiwai@suse.de


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      9a737e7f
    • Takashi Iwai's avatar
      ALSA: usb-audio: Split endpoint setups for hw_params and prepare (take#2) · 2be79d58
      Takashi Iwai authored 
      
This is a second attempt to fix the bug appearing on Android with the
recent kernel; the first try was ff878b40 and reverted at commit
79764ec7.

The details taken from the v1 patch:

One of the former changes for the endpoint management was the more
consistent setup of endpoints at hw_params.
snd_usb_endpoint_configure() is a single function that does the full
setup, and it's called from both PCM hw_params and prepare callbacks.
Although the EP setup at the prepare phase is usually skipped (by
checking need_setup flag), it may be still effective in some cases
like suspend/resume that requires the interface setup again.

As it's a full and single setup, the invocation of
snd_usb_endpoint_configure() includes not only the USB interface setup
but also the buffer release and allocation.  OTOH, doing the buffer
release and re-allocation at PCM prepare phase is rather superfluous,
and better to be done only in the hw_params phase.

For those optimizations, this patch splits the endpoint setup to two
phases: snd_usb_endpoint_set_params() and snd_usb_endpoint_prepare(),
to be called from hw_params and from prepare, respectively.

Note that this patch changes the driver operation slightly,
effectively moving the USB interface setup again to PCM prepare stage
instead of hw_params stage, while the buffer allocation and such
initializations are still done at hw_params stage.

And, the change of the USB interface setup timing (moving to prepare)
gave an interesting "fix", too: it was reported that the recent
kernels caused silent output at the beginning on playbacks on some
devices on Android, and this change casually fixed the regression.
It seems that those devices are picky about the sample rate change (or
the interface change?), and don't follow the too immediate rate
changes.

Meanwhile, Android operates the PCM in the following order:
- open, then hw_params with the possibly highest sample rate
- close without prepare
- re-open, hw_params with the normal sample rate
- prepare, and start streaming
This procedure ended up the hw_params twice with different rates, and
because the recent kernel did set up the sample rate twice one and
after, it screwed up the device.  OTOH, the earlier kernels didn't set
up the USB interface at hw_params, hence this problem didn't appear.

Now, with this patch, the USB interface setup is again back to the
prepare phase, and it works around the problem automagically.
Although we should address the sample rate problem in a more solid
way in future, let's keep things working as before for now.

***

What's new in the take#2 patch:
- The regression caused by the v1 patch (bko#216500) was due to the
  missing check of need_setup flag at hw_params.  Now the check is
  added, and the snd_usb_endpoint_set_params() call is skipped when
  the running EP is re-opened.

- There was another bug in v1 where the clock reference rate wasn't
  updated at hw_params phase, which may lead to a lack of the proper
  hw constraints when an application doesn't issue the prepare but
  only the hw_params call.  This patch fixes it as well by tracking
  the clock rate change in the prepare callback with a new flag
  "need_update" for the clock reference object, just like others.

- The configure_endpoints() are simplified and folded back into
  snd_usb_pcm_prepare().

Fixes: bf6313a0 ("ALSA: usb-audio: Refactor endpoint management")
Fixes: ff878b40 ("ALSA: usb-audio: Split endpoint setups for hw_params and prepare")
Reported-by: default avatarchihhao chen <chihhao.chen@mediatek.com>
Link: https://lore.kernel.org/r/87e6d6ae69d68dc588ac9acc8c0f24d6188375c3.camel@mediatek.com
Link: https://lore.kernel.org/r/20220901124136.4984-1-tiwai@suse.de
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216500
Link: https://lore.kernel.org/r/20220920181106.4894-1-tiwai@suse.de


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      2be79d58
    • Takashi Iwai's avatar
      Revert "ALSA: usb-audio: Clean up endpoint setups at PCM prepare" · 01a72aef
      Takashi Iwai authored 
      
This reverts commit 32eeeed9.

As the fix for endpoint configuration split is reverted at next, do
another revert here for a clean patch application.

Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      01a72aef
    • Takashi Iwai's avatar
      Revert "ALSA: usb-audio: Split endpoint setups for hw_params and prepare" · 79764ec7
      Takashi Iwai authored 
      This reverts commit ff878b40.

Unfortunately the recent fix seems bringing another regressions with
PulseAudio / pipewire, at least for Steinberg and MOTU devices.

As a temporary solution, do a straight revert.  The issue for Android
will be revisited again later by another different fix (if any).

Fixes: ff878b40 ("ALSA: usb-audio: Split endpoint setups for hw_params and prepare")
Cc: <stable@vger.kernel.org>
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=216500
Link: https://lore.kernel.org/r/20220920113929.25162-1-tiwai@suse.de


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      79764ec7
  29. Sep 15, 2022
    • Takashi Iwai's avatar
      ALSA: usb-audio: Fix last interface check for registration · 39efc9c8
      Takashi Iwai authored 
      The recent fix in commit 6392dcd1 ("ALSA: usb-audio: Register card
at the last interface") tried to delay the card registration until the
last found interface is probed.  It assumed that the probe callback
gets called for those later interfaces, but it's not always true; as
the driver loops over the descriptor and probes the matching ones,
it's not separately called via multiple probe calls.  This results in
the missing card registration, i.e. no sound device.

For addressing this problem, replace the check whether the last
interface is processed with usb_interface_claimed() instead of the
comparison with the probe interface number.

Fixes: 6392dcd1 ("ALSA: usb-audio: Register card at the last interface")
Link: https://lore.kernel.org/r/20220915085947.7922-1-tiwai@suse.de


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      39efc9c8
  31. Sep 09, 2022
  33. Sep 07, 2022
  35. Sep 06, 2022
    • Takashi Iwai's avatar
      ALSA: usb-audio: Register card at the last interface · 6392dcd1
      Takashi Iwai authored 
      The USB-audio driver matches per interface, and as default, it
registers the card instance at the very first instance.  This can be a
problem for the devices that have multiple interfaces to be probed, as
the udev rule isn't applied properly for the later appearing
interfaces.  Although we introduced the delayed_register option and
the quirks for covering those shortcomings, it's nothing but a
workaround for specific devices.

This patch is an another attempt to fix the problem in a more generic
way.  Now the driver checks the whole USB device descriptor at the
very first time when an interface is attached to a sound card.  It
looks at each matching interface in the descriptor and remembers the
last matching one.  The snd_card_register() is invoked only when this
last interface is probed.

After this change, the quirks for the delayed registration become
superfluous, hence they are removed along with the patch.  OTOH, the
delayed_register option is still kept, as it might be useful for some
corner cases (e.g. a special driver overtakes the interface probe from
the standard driver, and the last interface probe may miss).

Link: https://lore.kernel.org/r/20220904161247.16461-1-tiwai@suse.de


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      6392dcd1
    • Dongxiang Ke's avatar
      ALSA: usb-audio: Fix an out-of-bounds bug in __snd_usb_parse_audio_interface() · e53f47f6
      Dongxiang Ke authored and Takashi Iwai's avatar Takashi Iwai committed 
      
There may be a bad USB audio device with a USB ID of (0x04fa, 0x4201) and
the number of it's interfaces less than 4, an out-of-bounds read bug occurs
when parsing the interface descriptor for this device.

Fix this by checking the number of interfaces.

Signed-off-by: default avatarDongxiang Ke <kdx.glider@gmail.com>
Link: https://lore.kernel.org/r/20220906024928.10951-1-kdx.glider@gmail.com


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      e53f47f6
  37. Sep 01, 2022
    • Takashi Iwai's avatar
      ALSA: usb-audio: Clean up endpoint setups at PCM prepare · 32eeeed9
      Takashi Iwai authored 
      This patch cleans up the superfluous checks and calls for setting up
the endpoints at PCM prepare callback:

- Drop stop_endpoints() and sync_pending_stops() calls; the stream is
  guaranteed to have been already stopped and synced at each PCM
  prepare call by ALSA PCM core

- Call snd_usb_endpoint_prepare() unconditionally;
  the check for endpoint->need_setup is done in
  snd_pcm_hw_endpoint_prepare() itself

- Apply snd_usb_set_format_quirk() only when the endpoint is actually
  set up (i.e. the return code from snd_usb_endpoint_prepare() > 0)

- Move a few lines back into snd_usb_pcm_prepare();
  it's even easier to follow than a small useless function

Link: https://lore.kernel.org/r/20220901130831.6136-1-tiwai@suse.de


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      32eeeed9
    • Takashi Iwai's avatar
      ALSA: usb-audio: Split endpoint setups for hw_params and prepare · ff878b40
      Takashi Iwai authored 
      
One of the former changes for the endpoint management was the more
consistent setup of endpoints at hw_params.
snd_usb_endpoint_configure() is a single function that does the full
setup, and it's called from both PCM hw_params and prepare callbacks.
Although the EP setup at the prepare phase is usually skipped (by
checking need_setup flag), it may be still effective in some cases
like suspend/resume that requires the interface setup again.

As it's a full and single setup, the invocation of
snd_usb_endpoint_configure() includes not only the USB interface setup
but also the buffer release and allocation.  OTOH, doing the buffer
release and re-allocation at PCM prepare phase is rather superfluous,
and better to be done only in the hw_params phase.

For those optimizations, this patch splits the endpoint setup to two
phases: snd_usb_endpoint_set_params() and snd_usb_endpoint_prepare(),
to be called from hw_params and from prepare, respectively.

Note that this patch changes the driver operation slightly,
effectively moving the USB interface setup again to PCM prepare stage
instead of hw_params stage, while the buffer allocation and such
initializations are still done at hw_params stage.

And, the change of the USB interface setup timing (moving to prepare)
gave an interesting "fix", too: it was reported that the recent
kernels caused silent output at the beginning on playbacks on some
devices on Android, and this change casually fixed the regression.
It seems that those devices are picky about the sample rate change (or
the interface change?), and don't follow the too immediate rate
changes.

Meanwhile, Android operates the PCM in the following order:
- open, then hw_params with the possibly highest sample rate
- close without prepare
- re-open, hw_params with the normal sample rate
- prepare, and start streaming
This procedure ended up the hw_params twice with different rates, and
because the recent kernel did set up the sample rate twice one and
after, it screwed up the device.  OTOH, the earlier kernels didn't set
up the USB interface at hw_params, hence this problem didn't appear.

Now, with this patch, the USB interface setup is again back to the
prepare phase, and it works around the problem automagically.
Although we should address the sample rate problem in a more solid
way in future, let's keep things working as before for now.

Fixes: bf6313a0 ("ALSA: usb-audio: Refactor endpoint management")
Cc: <stable@vger.kernel.org>
Reported-by: default avatarchihhao chen <chihhao.chen@mediatek.com>
Link: https://lore.kernel.org/r/87e6d6ae69d68dc588ac9acc8c0f24d6188375c3.camel@mediatek.com
Link: https://lore.kernel.org/r/20220901124136.4984-1-tiwai@suse.de


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      ff878b40
    • Takashi Iwai's avatar
      ALSA: usb-audio: Drop superfluous interface setup at parsing · ac5e2fb4
      Takashi Iwai authored 
      We reset each interface that is being parsed for each stream, but this
is superfluous and even can lead to spurious errors.  Since the
interface is set up properly at opening the endpoint for each actual
stream operation, let's drop the superfluous one.

Link: https://lore.kernel.org/r/20220831130021.4762-1-tiwai@suse.de


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      ac5e2fb4
    • Takashi Iwai's avatar
      ALSA: usb-audio: Register card again for iface over delayed_register option · 2027f114
      Takashi Iwai authored 
      When the delayed registration is specified via either delayed_register
option or the quirk, we delay the invocation of snd_card_register()
until the given interface.  But if a wrong value has been set there
and there are more interfaces over the given interface number,
snd_card_register() call would be missing for those interfaces.

This patch catches up those missing calls by fixing the comparison of
the interface number.  Now the call is skipped only if the processed
interface is less than the given interface, instead of the exact
match.

Fixes: b70038ef ("ALSA: usb-audio: Add delayed_register option")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216082
Link: https://lore.kernel.org/r/20220831125901.4660-2-tiwai@suse.de


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      2027f114
    • Takashi Iwai's avatar
      ALSA: usb-audio: Inform the delayed registration more properly · 7e1afce5
      Takashi Iwai authored 
      The info message that was added in the commit a4aad563 ("ALSA:
usb-audio: Inform devices that need delayed registration") is actually
useful to know the need for the delayed registration.  However, it
turned out that this doesn't catch the all cases; namely, this warned
only when a PCM stream is attached onto the existing PCM instance, but
it doesn't count for a newly created PCM instance.  This made
confusion as if there were no further delayed registration.

This patch moves the check to the code path for either adding a stream
or creating a PCM instance.  Also, make it simpler by checking the
card->registered flag instead of querying each snd_device state.

Fixes: a4aad563 ("ALSA: usb-audio: Inform devices that need delayed registration")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216082
Link: https://lore.kernel.org/r/20220831125901.4660-1-tiwai@suse.de


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      7e1afce5
  39. Aug 28, 2022
  41. Aug 22, 2022
  43. Aug 10, 2022
  45. Aug 09, 2022