ASoC: soc-pcm: do not hw_free BE if it's still used

Do not free BE hw if it's still used by other FE during dpcm runtime
shutdown. Otherwise the BE runtime state will be STATE_HW_FREE and
won't be updated to STATE_CLOSE when shutdown ends, because BE dai
shutdown function won't close pcm when detecting BE is still under
use. With STATE_HW_FREE, BE can't be triggered start again.

This corner case can easily appear when one BE is used by two FE,
without this patch "ASoC: dpcm: Fix race between FE/BE updates and
trigger"(ea9d0d771fcd32cd56070819749477d511ec9117). One FE tries to
shutdown but it's raced against xrun on another FE. It improves the
be dai hw_free logic.

Signed-off-by: Qiao Zhou <zhouqiao@marvell.com>
Acked-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c
index 002311afdeaa..84357193c044 100644
--- a/sound/soc/soc-pcm.c
+++ b/sound/soc/soc-pcm.c
@@ -1641,6 +1641,10 @@ int dpcm_be_dai_hw_free(struct snd_soc_pcm_runtime *fe, int stream)
                 if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream))
                                 continue;
 
+                /* do not free hw if this BE is used by other FE */
+                if (be->dpcm[stream].users > 1)
+                        continue;
+
                 if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_HW_PARAMS) &&
                     (be->dpcm[stream].state != SND_SOC_DPCM_STATE_PREPARE) &&
                     (be->dpcm[stream].state != SND_SOC_DPCM_STATE_HW_FREE) &&