[alsa-devel] [PATCH 0/2] USB audio fixes
While trying to understand how asynchronous endpoints are supported, I identified two major issues. On my M-Audio transit, the following script tries to play using the 3 different endpoints supported and fails (error and no audio) after the first playback without the patches. With the patches on top of 4.1.5 or Takashi's for-next (4.2.0-rc5), I stopped the audio after an hour.
while true do aplay -d5 -Dhw:2,0 ~/16_48.wav # play 48kHz, 16 bit on async ep aplay -d5 -Dhw:2,0 ~/24_48.wav # play 48kHz, 24 bit on 'none'/async ep aplay -d5 -Dhw:2,0 ~/24_96.wav # play 96 kHz, 24 bit on adaptive ep aplay -d5 -Dhw:2,0 ~/24_48.wav aplay -d5 -Dhw:2,0 ~/16_48.wav aplay -d5 -Dhw:2,0 ~/24_96.wav done
The first issue is pretty bad with corrupted pointers. When transitioning from a alternate setting with a sync_endpoint to another which doesn't have one by construction (synchronous, adaptive, async on capture), the pointers are not reset and the code tries to set the parameters of a non-existent endpoint.
The second issue is that the M-audio Transit descriptors are illegal but the logic can be changed without harm.
I sometimes hear noise on playback start, probably the code needs to be changed to add enough silent samples to let the PLL lock. I haven't had time to work on this and this is more of an enhancement.
Comments welcome.
Pierre-Louis Bossart (2): ALSA: usb: fix corrupted pointers due to interface setting change ALSA: usb: handle descriptor with SYNC_NONE illegal value
sound/usb/pcm.c | 32 ++++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-)
When a transition occurs between alternate settings that do not use the same synchronization method, the substream pointers were not reset. This prevents audio from being played during the second transition.
Identified and tested with M-Audio Transit device (0763:2006 Midiman M-Audio Transit)
Details of the issue:
First playback to adaptive endpoint: $ aplay -Dhw:1,0 ~/24_96.wav Playing WAVE '/home/plb/24_96.wav' : Signed 24 bit Little Endian in 3bytes, Rate 96000 Hz, Stereo
[ 3169.297556] usb 1-2: setting usb interface 1:1 [ 3169.297568] usb 1-2: Creating new playback data endpoint #3 [ 3169.298563] usb 1-2: Setting params for ep #3 (type 0, 3 urbs), ret=0 [ 3169.298574] usb 1-2: Starting data EP @ffff880035fc8000
first playback to asynchronous endpoint: $ aplay -Dhw:1,0 ~/16_48.wav Playing WAVE '/home/plb/16_48.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Stereo
[ 3204.520251] usb 1-2: setting usb interface 1:3 [ 3204.520264] usb 1-2: Creating new playback data endpoint #3 [ 3204.520272] usb 1-2: Creating new capture sync endpoint #83 [ 3204.521162] usb 1-2: Setting params for ep #3 (type 0, 4 urbs), ret=0 [ 3204.521177] usb 1-2: Setting params for ep #83 (type 1, 4 urbs), ret=0 [ 3204.521182] usb 1-2: Starting data EP @ffff880035fce000 [ 3204.521204] usb 1-2: Starting sync EP @ffff8800bd616000
second playback to adaptive endpoint: no audio and error on terminal: $ aplay -Dhw:1,0 ~/24_96.wav Playing WAVE '/home/plb/24_96.wav' : Signed 24 bit Little Endian in 3bytes, Rate 96000 Hz, Stereo aplay: pcm_write:1939: write error: Input/output error
[ 3239.483589] usb 1-2: setting usb interface 1:1 [ 3239.483601] usb 1-2: Re-using EP 3 in iface 1,1 @ffff880035fc8000 [ 3239.484590] usb 1-2: Setting params for ep #3 (type 0, 4 urbs), ret=0 [ 3239.484606] usb 1-2: Setting params for ep #83 (type 1, 4 urbs), ret=0
This last line shows that a sync endpoint is used when it shouldn't. The sync endpoint is no longer valid and the pointers are corrupted
Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- sound/usb/pcm.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c index b4ef410..7cd7c03 100644 --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -395,6 +395,19 @@ static int set_sync_endpoint(struct snd_usb_substream *subs, if (err < 0) return err;
+ if ((is_playback && (attr != USB_ENDPOINT_SYNC_ASYNC)) || + (!is_playback && (attr != USB_ENDPOINT_SYNC_ADAPTIVE))) { + + /* + * Clean-up subs pointers to make sure sync_endpoint is never + * configured. This is needed in case of a transition between + * alternate settings using different synchronization modes + * where the previous sync_endpoint may no longer be valid. + */ + subs->sync_endpoint = NULL; + subs->data_endpoint->sync_master = NULL; + } + if (altsd->bNumEndpoints < 2) return 0;
On Fri, 14 Aug 2015 00:42:32 +0200, Pierre-Louis Bossart wrote:
When a transition occurs between alternate settings that do not use the same synchronization method, the substream pointers were not reset. This prevents audio from being played during the second transition.
Identified and tested with M-Audio Transit device (0763:2006 Midiman M-Audio Transit)
Hmm, I have this old device, too, but couldn't reproduce the problem. Is there any special setup with it?
Takashi
Details of the issue:
First playback to adaptive endpoint: $ aplay -Dhw:1,0 ~/24_96.wav Playing WAVE '/home/plb/24_96.wav' : Signed 24 bit Little Endian in 3bytes, Rate 96000 Hz, Stereo
[ 3169.297556] usb 1-2: setting usb interface 1:1 [ 3169.297568] usb 1-2: Creating new playback data endpoint #3 [ 3169.298563] usb 1-2: Setting params for ep #3 (type 0, 3 urbs), ret=0 [ 3169.298574] usb 1-2: Starting data EP @ffff880035fc8000
first playback to asynchronous endpoint: $ aplay -Dhw:1,0 ~/16_48.wav Playing WAVE '/home/plb/16_48.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Stereo
[ 3204.520251] usb 1-2: setting usb interface 1:3 [ 3204.520264] usb 1-2: Creating new playback data endpoint #3 [ 3204.520272] usb 1-2: Creating new capture sync endpoint #83 [ 3204.521162] usb 1-2: Setting params for ep #3 (type 0, 4 urbs), ret=0 [ 3204.521177] usb 1-2: Setting params for ep #83 (type 1, 4 urbs), ret=0 [ 3204.521182] usb 1-2: Starting data EP @ffff880035fce000 [ 3204.521204] usb 1-2: Starting sync EP @ffff8800bd616000
second playback to adaptive endpoint: no audio and error on terminal: $ aplay -Dhw:1,0 ~/24_96.wav Playing WAVE '/home/plb/24_96.wav' : Signed 24 bit Little Endian in 3bytes, Rate 96000 Hz, Stereo aplay: pcm_write:1939: write error: Input/output error
[ 3239.483589] usb 1-2: setting usb interface 1:1 [ 3239.483601] usb 1-2: Re-using EP 3 in iface 1,1 @ffff880035fc8000 [ 3239.484590] usb 1-2: Setting params for ep #3 (type 0, 4 urbs), ret=0 [ 3239.484606] usb 1-2: Setting params for ep #83 (type 1, 4 urbs), ret=0
This last line shows that a sync endpoint is used when it shouldn't. The sync endpoint is no longer valid and the pointers are corrupted
Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com
sound/usb/pcm.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c index b4ef410..7cd7c03 100644 --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -395,6 +395,19 @@ static int set_sync_endpoint(struct snd_usb_substream *subs, if (err < 0) return err;
- if ((is_playback && (attr != USB_ENDPOINT_SYNC_ASYNC)) ||
(!is_playback && (attr != USB_ENDPOINT_SYNC_ADAPTIVE))) {/** Clean-up subs pointers to make sure sync_endpoint is never* configured. This is needed in case of a transition between* alternate settings using different synchronization modes* where the previous sync_endpoint may no longer be valid.*/subs->sync_endpoint = NULL;subs->data_endpoint->sync_master = NULL;- }
- if (altsd->bNumEndpoints < 2) return 0;
-- 1.9.1
On Fri, 14 Aug 2015 17:03:10 +0200, Takashi Iwai wrote:
On Fri, 14 Aug 2015 00:42:32 +0200, Pierre-Louis Bossart wrote:
When a transition occurs between alternate settings that do not use the same synchronization method, the substream pointers were not reset. This prevents audio from being played during the second transition.
Identified and tested with M-Audio Transit device (0763:2006 Midiman M-Audio Transit)
Hmm, I have this old device, too, but couldn't reproduce the problem. Is there any special setup with it?
OK, I could see it after switching a few times. But, also your patch didn't cure, either...
Takashi
Takashi
Details of the issue:
First playback to adaptive endpoint: $ aplay -Dhw:1,0 ~/24_96.wav Playing WAVE '/home/plb/24_96.wav' : Signed 24 bit Little Endian in 3bytes, Rate 96000 Hz, Stereo
[ 3169.297556] usb 1-2: setting usb interface 1:1 [ 3169.297568] usb 1-2: Creating new playback data endpoint #3 [ 3169.298563] usb 1-2: Setting params for ep #3 (type 0, 3 urbs), ret=0 [ 3169.298574] usb 1-2: Starting data EP @ffff880035fc8000
first playback to asynchronous endpoint: $ aplay -Dhw:1,0 ~/16_48.wav Playing WAVE '/home/plb/16_48.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Stereo
[ 3204.520251] usb 1-2: setting usb interface 1:3 [ 3204.520264] usb 1-2: Creating new playback data endpoint #3 [ 3204.520272] usb 1-2: Creating new capture sync endpoint #83 [ 3204.521162] usb 1-2: Setting params for ep #3 (type 0, 4 urbs), ret=0 [ 3204.521177] usb 1-2: Setting params for ep #83 (type 1, 4 urbs), ret=0 [ 3204.521182] usb 1-2: Starting data EP @ffff880035fce000 [ 3204.521204] usb 1-2: Starting sync EP @ffff8800bd616000
second playback to adaptive endpoint: no audio and error on terminal: $ aplay -Dhw:1,0 ~/24_96.wav Playing WAVE '/home/plb/24_96.wav' : Signed 24 bit Little Endian in 3bytes, Rate 96000 Hz, Stereo aplay: pcm_write:1939: write error: Input/output error
[ 3239.483589] usb 1-2: setting usb interface 1:1 [ 3239.483601] usb 1-2: Re-using EP 3 in iface 1,1 @ffff880035fc8000 [ 3239.484590] usb 1-2: Setting params for ep #3 (type 0, 4 urbs), ret=0 [ 3239.484606] usb 1-2: Setting params for ep #83 (type 1, 4 urbs), ret=0
This last line shows that a sync endpoint is used when it shouldn't. The sync endpoint is no longer valid and the pointers are corrupted
Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com
sound/usb/pcm.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c index b4ef410..7cd7c03 100644 --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -395,6 +395,19 @@ static int set_sync_endpoint(struct snd_usb_substream *subs, if (err < 0) return err;
- if ((is_playback && (attr != USB_ENDPOINT_SYNC_ASYNC)) ||
(!is_playback && (attr != USB_ENDPOINT_SYNC_ADAPTIVE))) {/** Clean-up subs pointers to make sure sync_endpoint is never* configured. This is needed in case of a transition between* alternate settings using different synchronization modes* where the previous sync_endpoint may no longer be valid.*/subs->sync_endpoint = NULL;subs->data_endpoint->sync_master = NULL;- }
- if (altsd->bNumEndpoints < 2) return 0;
-- 1.9.1
On 8/14/15 10:28 AM, Takashi Iwai wrote:
On Fri, 14 Aug 2015 17:03:10 +0200, Takashi Iwai wrote:
On Fri, 14 Aug 2015 00:42:32 +0200, Pierre-Louis Bossart wrote:
When a transition occurs between alternate settings that do not use the same synchronization method, the substream pointers were not reset. This prevents audio from being played during the second transition.
Identified and tested with M-Audio Transit device (0763:2006 Midiman M-Audio Transit)
Hmm, I have this old device, too, but couldn't reproduce the problem. Is there any special setup with it?
OK, I could see it after switching a few times. But, also your patch didn't cure, either...
I tested this with Ubuntu 14.04 and the default madfuload package that comes with it for the firmware.
I think you need both patches to get the device to work. I split the patches in two since I think the second problem is device specific while the first one is a generic one that can happen on other devices.
I generated three chirps test files with audacity, one stereo 96kHz 24bits (3 bytes), one stereo 48kHz 24 bits (3 bytes) and then stereo 48kHz 16 bits. This matches the capabilities of the three endpoints. If you try first with the 48kHz 16bits one then typically the others won't work.
Takashi
Takashi
Details of the issue:
First playback to adaptive endpoint: $ aplay -Dhw:1,0 ~/24_96.wav Playing WAVE '/home/plb/24_96.wav' : Signed 24 bit Little Endian in 3bytes, Rate 96000 Hz, Stereo
[ 3169.297556] usb 1-2: setting usb interface 1:1 [ 3169.297568] usb 1-2: Creating new playback data endpoint #3 [ 3169.298563] usb 1-2: Setting params for ep #3 (type 0, 3 urbs), ret=0 [ 3169.298574] usb 1-2: Starting data EP @ffff880035fc8000
first playback to asynchronous endpoint: $ aplay -Dhw:1,0 ~/16_48.wav Playing WAVE '/home/plb/16_48.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Stereo
[ 3204.520251] usb 1-2: setting usb interface 1:3 [ 3204.520264] usb 1-2: Creating new playback data endpoint #3 [ 3204.520272] usb 1-2: Creating new capture sync endpoint #83 [ 3204.521162] usb 1-2: Setting params for ep #3 (type 0, 4 urbs), ret=0 [ 3204.521177] usb 1-2: Setting params for ep #83 (type 1, 4 urbs), ret=0 [ 3204.521182] usb 1-2: Starting data EP @ffff880035fce000 [ 3204.521204] usb 1-2: Starting sync EP @ffff8800bd616000
second playback to adaptive endpoint: no audio and error on terminal: $ aplay -Dhw:1,0 ~/24_96.wav Playing WAVE '/home/plb/24_96.wav' : Signed 24 bit Little Endian in 3bytes, Rate 96000 Hz, Stereo aplay: pcm_write:1939: write error: Input/output error
[ 3239.483589] usb 1-2: setting usb interface 1:1 [ 3239.483601] usb 1-2: Re-using EP 3 in iface 1,1 @ffff880035fc8000 [ 3239.484590] usb 1-2: Setting params for ep #3 (type 0, 4 urbs), ret=0 [ 3239.484606] usb 1-2: Setting params for ep #83 (type 1, 4 urbs), ret=0
This last line shows that a sync endpoint is used when it shouldn't. The sync endpoint is no longer valid and the pointers are corrupted
Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com
sound/usb/pcm.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c index b4ef410..7cd7c03 100644 --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -395,6 +395,19 @@ static int set_sync_endpoint(struct snd_usb_substream *subs, if (err < 0) return err;
- if ((is_playback && (attr != USB_ENDPOINT_SYNC_ASYNC)) ||
(!is_playback && (attr != USB_ENDPOINT_SYNC_ADAPTIVE))) {/** Clean-up subs pointers to make sure sync_endpoint is never* configured. This is needed in case of a transition between* alternate settings using different synchronization modes* where the previous sync_endpoint may no longer be valid.*/subs->sync_endpoint = NULL;subs->data_endpoint->sync_master = NULL;- }
- if (altsd->bNumEndpoints < 2) return 0;
-- 1.9.1
On Fri, 14 Aug 2015 17:39:32 +0200, Pierre-Louis Bossart wrote:
On 8/14/15 10:28 AM, Takashi Iwai wrote:
On Fri, 14 Aug 2015 17:03:10 +0200, Takashi Iwai wrote:
On Fri, 14 Aug 2015 00:42:32 +0200, Pierre-Louis Bossart wrote:
When a transition occurs between alternate settings that do not use the same synchronization method, the substream pointers were not reset. This prevents audio from being played during the second transition.
Identified and tested with M-Audio Transit device (0763:2006 Midiman M-Audio Transit)
Hmm, I have this old device, too, but couldn't reproduce the problem. Is there any special setup with it?
OK, I could see it after switching a few times. But, also your patch didn't cure, either...
I tested this with Ubuntu 14.04 and the default madfuload package that comes with it for the firmware.
I think you need both patches to get the device to work. I split the patches in two since I think the second problem is device specific while the first one is a generic one that can happen on other devices.
I tested both at once, of course :) With my device, 24/96 -> 16/48 works, then again switching to 24/96 stalls. After that, it doesn't work no matter which mode is until I replug the device.
Takashi
I generated three chirps test files with audacity, one stereo 96kHz 24bits (3 bytes), one stereo 48kHz 24 bits (3 bytes) and then stereo 48kHz 16 bits. This matches the capabilities of the three endpoints. If you try first with the 48kHz 16bits one then typically the others won't work.
Takashi
Takashi
Details of the issue:
First playback to adaptive endpoint: $ aplay -Dhw:1,0 ~/24_96.wav Playing WAVE '/home/plb/24_96.wav' : Signed 24 bit Little Endian in 3bytes, Rate 96000 Hz, Stereo
[ 3169.297556] usb 1-2: setting usb interface 1:1 [ 3169.297568] usb 1-2: Creating new playback data endpoint #3 [ 3169.298563] usb 1-2: Setting params for ep #3 (type 0, 3 urbs), ret=0 [ 3169.298574] usb 1-2: Starting data EP @ffff880035fc8000
first playback to asynchronous endpoint: $ aplay -Dhw:1,0 ~/16_48.wav Playing WAVE '/home/plb/16_48.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Stereo
[ 3204.520251] usb 1-2: setting usb interface 1:3 [ 3204.520264] usb 1-2: Creating new playback data endpoint #3 [ 3204.520272] usb 1-2: Creating new capture sync endpoint #83 [ 3204.521162] usb 1-2: Setting params for ep #3 (type 0, 4 urbs), ret=0 [ 3204.521177] usb 1-2: Setting params for ep #83 (type 1, 4 urbs), ret=0 [ 3204.521182] usb 1-2: Starting data EP @ffff880035fce000 [ 3204.521204] usb 1-2: Starting sync EP @ffff8800bd616000
second playback to adaptive endpoint: no audio and error on terminal: $ aplay -Dhw:1,0 ~/24_96.wav Playing WAVE '/home/plb/24_96.wav' : Signed 24 bit Little Endian in 3bytes, Rate 96000 Hz, Stereo aplay: pcm_write:1939: write error: Input/output error
[ 3239.483589] usb 1-2: setting usb interface 1:1 [ 3239.483601] usb 1-2: Re-using EP 3 in iface 1,1 @ffff880035fc8000 [ 3239.484590] usb 1-2: Setting params for ep #3 (type 0, 4 urbs), ret=0 [ 3239.484606] usb 1-2: Setting params for ep #83 (type 1, 4 urbs), ret=0
This last line shows that a sync endpoint is used when it shouldn't. The sync endpoint is no longer valid and the pointers are corrupted
Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com
sound/usb/pcm.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c index b4ef410..7cd7c03 100644 --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -395,6 +395,19 @@ static int set_sync_endpoint(struct snd_usb_substream *subs, if (err < 0) return err;
- if ((is_playback && (attr != USB_ENDPOINT_SYNC_ASYNC)) ||
(!is_playback && (attr != USB_ENDPOINT_SYNC_ADAPTIVE))) {/** Clean-up subs pointers to make sure sync_endpoint is never* configured. This is needed in case of a transition between* alternate settings using different synchronization modes* where the previous sync_endpoint may no longer be valid.*/subs->sync_endpoint = NULL;subs->data_endpoint->sync_master = NULL;- }
- if (altsd->bNumEndpoints < 2) return 0;
-- 1.9.1
On Fri, 14 Aug 2015 17:47:59 +0200, Takashi Iwai wrote:
On Fri, 14 Aug 2015 17:39:32 +0200, Pierre-Louis Bossart wrote:
On 8/14/15 10:28 AM, Takashi Iwai wrote:
On Fri, 14 Aug 2015 17:03:10 +0200, Takashi Iwai wrote:
On Fri, 14 Aug 2015 00:42:32 +0200, Pierre-Louis Bossart wrote:
When a transition occurs between alternate settings that do not use the same synchronization method, the substream pointers were not reset. This prevents audio from being played during the second transition.
Identified and tested with M-Audio Transit device (0763:2006 Midiman M-Audio Transit)
Hmm, I have this old device, too, but couldn't reproduce the problem. Is there any special setup with it?
OK, I could see it after switching a few times. But, also your patch didn't cure, either...
I tested this with Ubuntu 14.04 and the default madfuload package that comes with it for the firmware.
I think you need both patches to get the device to work. I split the patches in two since I think the second problem is device specific while the first one is a generic one that can happen on other devices.
I tested both at once, of course :) With my device, 24/96 -> 16/48 works, then again switching to 24/96 stalls. After that, it doesn't work no matter which mode is until I replug the device.
Hmm, now after a few retrials, it starts working. Will review both patches now.
Takashi
On Fri, 14 Aug 2015 00:42:32 +0200, Pierre-Louis Bossart wrote:
--- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -395,6 +395,19 @@ static int set_sync_endpoint(struct snd_usb_substream *subs, if (err < 0) return err;
- if ((is_playback && (attr != USB_ENDPOINT_SYNC_ASYNC)) ||
(!is_playback && (attr != USB_ENDPOINT_SYNC_ADAPTIVE))) {/** Clean-up subs pointers to make sure sync_endpoint is never* configured. This is needed in case of a transition between* alternate settings using different synchronization modes* where the previous sync_endpoint may no longer be valid.*/subs->sync_endpoint = NULL;subs->data_endpoint->sync_master = NULL;- }
I think this initialization can be put unconditionally on top, not in a separate like below, as this is just overlooked leaks. The comment can be better in more details, of course.
Takashi
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c index b4ef410e5a98..0d935369d641 100644 --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -391,6 +391,10 @@ static int set_sync_endpoint(struct snd_usb_substream *subs, */ attr = fmt->ep_attr & USB_ENDPOINT_SYNCTYPE;
+ /* Clean-up subs sync and master pointers at first */ + subs->sync_endpoint = NULL; + subs->data_endpoint->sync_master = NULL; + err = set_sync_ep_implicit_fb_quirk(subs, dev, altsd, attr); if (err < 0) return err;
On 8/14/15 10:57 AM, Takashi Iwai wrote:
On Fri, 14 Aug 2015 00:42:32 +0200, Pierre-Louis Bossart wrote:
--- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -395,6 +395,19 @@ static int set_sync_endpoint(struct snd_usb_substream *subs, if (err < 0) return err;
- if ((is_playback && (attr != USB_ENDPOINT_SYNC_ASYNC)) ||
(!is_playback && (attr != USB_ENDPOINT_SYNC_ADAPTIVE))) {/** Clean-up subs pointers to make sure sync_endpoint is never* configured. This is needed in case of a transition between* alternate settings using different synchronization modes* where the previous sync_endpoint may no longer be valid.*/subs->sync_endpoint = NULL;subs->data_endpoint->sync_master = NULL;- }
I think this initialization can be put unconditionally on top, not in a separate like below, as this is just overlooked leaks. The comment can be better in more details, of course.
I wasn't sure about side effects. I don't know what exactly the set_sync_ep_implicit_fb_quick() does and I was worried about changing the behavior on devices I didn't test. But if this is fine then I can change it, no issue. Yes the comment isn't clear. I should be something like "in these modes there is no sync_endpoint and the pointers need to be reset to avoid using stale information from previous settings"
Agree on the other changes, will provide an update. Thanks for the quick review!
Takashi
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c index b4ef410e5a98..0d935369d641 100644 --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -391,6 +391,10 @@ static int set_sync_endpoint(struct snd_usb_substream *subs, */ attr = fmt->ep_attr & USB_ENDPOINT_SYNCTYPE;
- /* Clean-up subs sync and master pointers at first */
- subs->sync_endpoint = NULL;
- subs->data_endpoint->sync_master = NULL;
- err = set_sync_ep_implicit_fb_quirk(subs, dev, altsd, attr); if (err < 0) return err;
The M-Audio Transit exposes an interface with a SYNC_NONE attribute. This is not a valid value according to the USB audio classspec. However there is a sync endpoint associated to this record. Changing the logic to try to use this sync endpoint allows for seamless transitions between altset 2 and altset 3. If any errors happen, the behavior remains the same.
$ more /proc/asound/card1/stream0 M-Audio Transit USB at usb-0000:00:14.0-2, full speed : USB Audio
Playback: Status: Stop Interface 1 Altset 1 Format: S24_3LE Channels: 2 Endpoint: 3 OUT (ADAPTIVE) Rates: 48001 - 96000 (continuous) Interface 1 Altset 2 Format: S24_3LE Channels: 2 Endpoint: 3 OUT (NONE) Rates: 8000 - 48000 (continuous) Interface 1 Altset 3 Format: S16_LE Channels: 2 Endpoint: 3 OUT (ASYNC) Rates: 8000 - 48000 (continuous)
Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- sound/usb/pcm.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-)
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c index 7cd7c03..9f29017 100644 --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -411,10 +411,17 @@ static int set_sync_endpoint(struct snd_usb_substream *subs, if (altsd->bNumEndpoints < 2) return 0;
- if ((is_playback && attr != USB_ENDPOINT_SYNC_ASYNC) || + if ((is_playback && attr == USB_ENDPOINT_SYNC_SYNC) || + (is_playback && attr == USB_ENDPOINT_SYNC_ADAPTIVE) || (!is_playback && attr != USB_ENDPOINT_SYNC_ADAPTIVE)) return 0;
+ /* + * In case of illegal SYNC_NONE for OUT endpoint, we keep going to see + * if we don't find a sync endpoint, as on M-Audio Transit. In case of + * error fall back to SYNC mode and don't create sync endpoint + */ + /* check sync-pipe endpoint */ /* ... and check descriptor size before accessing bSynchAddress because there is a version of the SB Audigy 2 NX firmware lacking @@ -428,6 +435,8 @@ static int set_sync_endpoint(struct snd_usb_substream *subs, get_endpoint(alts, 1)->bmAttributes, get_endpoint(alts, 1)->bLength, get_endpoint(alts, 1)->bSynchAddress); + if (is_playback && attr == USB_ENDPOINT_SYNC_NONE) + goto no_valid_sync_ep_found; return -EINVAL; } ep = get_endpoint(alts, 1)->bEndpointAddress; @@ -438,6 +447,8 @@ static int set_sync_endpoint(struct snd_usb_substream *subs, "%d:%d : invalid sync pipe. is_playback %d, ep %02x, bSynchAddress %02x\n", fmt->iface, fmt->altsetting, is_playback, ep, get_endpoint(alts, 0)->bSynchAddress); + if (is_playback && attr == USB_ENDPOINT_SYNC_NONE) + goto no_valid_sync_ep_found; return -EINVAL; }
@@ -449,11 +460,15 @@ static int set_sync_endpoint(struct snd_usb_substream *subs, implicit_fb ? SND_USB_ENDPOINT_TYPE_DATA : SND_USB_ENDPOINT_TYPE_SYNC); - if (!subs->sync_endpoint) + if (!subs->sync_endpoint) { + if (is_playback && attr == USB_ENDPOINT_SYNC_NONE) + goto no_valid_sync_ep_found; return -EINVAL; + }
subs->data_endpoint->sync_master = subs->sync_endpoint;
+no_valid_sync_ep_found: /* fall back to synchronous mode */ return 0; }
On Fri, 14 Aug 2015 00:42:33 +0200, Pierre-Louis Bossart wrote:
--- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -411,10 +411,17 @@ static int set_sync_endpoint(struct snd_usb_substream *subs, if (altsd->bNumEndpoints < 2) return 0;
- if ((is_playback && attr != USB_ENDPOINT_SYNC_ASYNC) ||
- if ((is_playback && attr == USB_ENDPOINT_SYNC_SYNC) ||
(is_playback && attr == USB_ENDPOINT_SYNC_ADAPTIVE) ||
Better to be: (is_playback && (attr == USB_ENDPOINT_SYNC_SYNC || attr == USB_ENDPOINT_SYNC_ADAPTIVE)) ||
(!is_playback && attr != USB_ENDPOINT_SYNC_ADAPTIVE)) return 0;
- /*
* In case of illegal SYNC_NONE for OUT endpoint, we keep going to see* if we don't find a sync endpoint, as on M-Audio Transit. In case of* error fall back to SYNC mode and don't create sync endpoint*/- /* check sync-pipe endpoint */ /* ... and check descriptor size before accessing bSynchAddress because there is a version of the SB Audigy 2 NX firmware lacking
@@ -428,6 +435,8 @@ static int set_sync_endpoint(struct snd_usb_substream *subs, get_endpoint(alts, 1)->bmAttributes, get_endpoint(alts, 1)->bLength, get_endpoint(alts, 1)->bSynchAddress);
if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)goto no_valid_sync_ep_found;
We handle this as a success case, so the error message should be avoided for SYNC_NONE. Also, it's fine just returning 0 here.
return -EINVAL;} ep = get_endpoint(alts, 1)->bEndpointAddress; @@ -438,6 +447,8 @@ static int set_sync_endpoint(struct snd_usb_substream *subs, "%d:%d : invalid sync pipe. is_playback %d, ep %02x, bSynchAddress %02x\n", fmt->iface, fmt->altsetting, is_playback, ep, get_endpoint(alts, 0)->bSynchAddress);
if (is_playback && attr == USB_ENDPOINT_SYNC_NONE)goto no_valid_sync_ep_found;
Ditto.
thanks,
Takashi
participants (2)
-
Pierre-Louis Bossart -
Takashi Iwai