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 is not pruned, new backend path is 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.

* No change since initial RFC [0], just droppped the RFC prefix.

[0]: https://lkml.kernel.org/r/20180419140612.11049-1-jbrunet@baylibre.com

include/sound/soc-dai.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

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;