| Message ID | 20180419140612.11049-1-jbrunet@baylibre.com |
|---|---|
| State | New |
| Headers | show |
| Series | [RFC] ASoC: dai playback_active and capture_active may be greater than 1 | expand |
On Thu, Apr 19, 2018 at 04:06:12PM +0200, Jerome Brunet wrote: > At the moment playback_active and capture_active are using only 1 bit so > the maximum active count is 1. > > However, snd_soc_runtime_activate() may be called several time on the > same dai. This happens when a dai is part of several dai_links. It is > often the case for "snd-soc-dummy-dai". > > This is a problem if snd_soc_runtime_activate() is called an even number > of times on a dai. In this case the active count overflow back to 0. As > consequence, ASoC functions, such as soc_dpcm_runtime_update(), won't run > correctly. > > Storing these usage counts on plain 'unsigned int' solves the problem. > > Fixes: f0fba2ad1b6b ("ASoC: multi-component - ASoC Multi-Component Support") > Signed-off-by: Jerome Brunet <jbrunet@baylibre.com> > --- Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com> Thanks, Charles _______________________________________________ Alsa-devel mailing list Alsa-devel@alsa-project.org http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
diff --git a/include/sound/soc-dai.h b/include/sound/soc-dai.h index 8ad11669e4d8..35ebb0be5114 100644 --- a/include/sound/soc-dai.h +++ b/include/sound/soc-dai.h @@ -294,8 +294,8 @@ struct snd_soc_dai { struct snd_soc_dai_driver *driver; /* DAI runtime info */ - unsigned int capture_active:1; /* stream is in use */ - unsigned int playback_active:1; /* stream is in use */ + unsigned int capture_active; /* stream usage count */ + unsigned int playback_active; /* stream usage count */ unsigned int probed:1; unsigned int active;
At the moment playback_active and capture_active are using only 1 bit so the maximum active count is 1. However, snd_soc_runtime_activate() may be called several time on the same dai. This happens when a dai is part of several dai_links. It is often the case for "snd-soc-dummy-dai". This is a problem if snd_soc_runtime_activate() is called an even number of times on a dai. In this case the active count overflow back to 0. As consequence, ASoC functions, such as soc_dpcm_runtime_update(), won't run correctly. Storing these usage counts on plain 'unsigned int' solves the problem. Fixes: f0fba2ad1b6b ("ASoC: multi-component - ASoC Multi-Component Support") Signed-off-by: Jerome Brunet <jbrunet@baylibre.com> --- Hi, I found this problem while working on ASoC support for a new platform. During a playback, using DPCM, if I changed the backend dai, nothing happened, old backend path was not pruned, new backend path was not added. Here is how it goes: 1 FE and 2 BE, all 3 using snd-soc-dummy-dai for the codec_dai (ATM). On playback start: - BE #1 activates and increments snd-soc-dummy-dai's playback_active - FE activates and increments snd-soc-dummy-dai's playback_active The playback works but snd-soc-dummy-dai's playback_active value is now 0. Through a mux kcontrol, change BE client of FE, from BE #1 to BE #2. -> trigger soc_dpcm_runtime_update(). -> checks fe's codec_dai playback_active which is zero so playback path processing is skipped, keeping the old invalid path. include/sound/soc-dai.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) -- 2.14.3 _______________________________________________ Alsa-devel mailing list Alsa-devel@alsa-project.org http://mailman.alsa-project.org/mailman/listinfo/alsa-devel