| Message ID | 1526980408-1935-2-git-send-email-kaichieh.chuang@mediatek.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, May 22, 2018 at 05:13:27PM +0800, KaiChieh Chuang wrote: > In case, one BE is used by two FE1/FE2 > FE1--->BE--> > FE2---> > > When FE1/FE2 call dpcm_be_dai_hw_free() together > the BE users will be 2 (> 1), hence cannot be hw_free. > The be state will leave at, ex. SND_SOC_DPCM_STATE_STOP > > Later FE1/FE2 call dpcm_be_dai_shutdown(), > will be skip due to wrong state. > Leaving the BE not being hw_free and shutdown. > > This patch add a flag in snd_soc_dpcm to denote > the hw_free cannot be excute for this fe->be dpcm. > The BE dai will be hw_free later when calling > dpcm_be_dai_shutdown() if still in invalid state. This works but feels messy and fragile - the problem here is that we use the users count to decide if we can do a hw_free() but we don't decrement that users count until shutdown which leaves the race condition you're fixing here. We probably need to add a second refcount here for hw_free() which also feels a bit messy but is probably robust. Another option is to just unconditionally do the hw_free() and clean up if we're in the wrong state rather than checking the flag (so basically your patch but ignoring the flag), that is simpler and should be robust - I can't think of any reason that'd be a problem?
diff --git a/include/sound/soc-dpcm.h b/include/sound/soc-dpcm.h index 8060590..52d9b5d 100644 --- a/include/sound/soc-dpcm.h +++ b/include/sound/soc-dpcm.h @@ -86,6 +86,8 @@ struct snd_soc_dpcm { #ifdef CONFIG_DEBUG_FS struct dentry *debugfs_state; #endif + + bool be_hw_free_deferred; }; /* diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c index 87c9af2..481604a 100644 --- a/sound/soc/soc-pcm.c +++ b/sound/soc/soc-pcm.c @@ -1866,8 +1866,16 @@ int dpcm_be_dai_shutdown(struct snd_soc_pcm_runtime *fe, int stream) continue; if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_HW_FREE) && - (be->dpcm[stream].state != SND_SOC_DPCM_STATE_OPEN)) - continue; + (be->dpcm[stream].state != SND_SOC_DPCM_STATE_OPEN)) { + if (dpcm->be_hw_free_deferred) { + soc_pcm_hw_free(be_substream); + be->dpcm[stream].state = + SND_SOC_DPCM_STATE_HW_FREE; + dpcm->be_hw_free_deferred = false; + } else { + continue; + } + } dev_dbg(be->dev, "ASoC: close BE %s\n", be->dai_link->name); @@ -1924,8 +1932,10 @@ int dpcm_be_dai_hw_free(struct snd_soc_pcm_runtime *fe, int stream) continue; /* do not free hw if this BE is used by other FE */ - if (be->dpcm[stream].users > 1) + if (be->dpcm[stream].users > 1) { + dpcm->be_hw_free_deferred = true; continue; + } if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_HW_PARAMS) && (be->dpcm[stream].state != SND_SOC_DPCM_STATE_PREPARE) && @@ -1941,6 +1951,7 @@ int dpcm_be_dai_hw_free(struct snd_soc_pcm_runtime *fe, int stream) soc_pcm_hw_free(be_substream); be->dpcm[stream].state = SND_SOC_DPCM_STATE_HW_FREE; + dpcm->be_hw_free_deferred = false; } return 0;
In case, one BE is used by two FE1/FE2 FE1--->BE--> FE2---> When FE1/FE2 call dpcm_be_dai_hw_free() together the BE users will be 2 (> 1), hence cannot be hw_free. The be state will leave at, ex. SND_SOC_DPCM_STATE_STOP Later FE1/FE2 call dpcm_be_dai_shutdown(), will be skip due to wrong state. Leaving the BE not being hw_free and shutdown. This patch add a flag in snd_soc_dpcm to denote the hw_free cannot be excute for this fe->be dpcm. The BE dai will be hw_free later when calling dpcm_be_dai_shutdown() if still in invalid state. Signed-off-by: KaiChieh Chuang <kaichieh.chuang@mediatek.com> --- include/sound/soc-dpcm.h | 2 ++ sound/soc/soc-pcm.c | 17 ++++++++++++++--- 2 files changed, 16 insertions(+), 3 deletions(-)