| Message ID | 20191004154127.28459-1-ranjani.sridharan@linux.intel.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Alter the trigger order for FE/BE DAI's based on command | expand |
On 10/4/19 8:41 AM, Ranjani Sridharan wrote: > Currently, the trigger orders SND_SOC_DPCM_TRIGGER_PRE/POST > determine the order in which FE DAI and BE DAI are triggered. > In the case of SND_SOC_DPCM_TRIGGER_PRE, the FE DAI is > triggered before the BE DAI and in the case of > SND_SOC_DPCM_TRIGGER_POST, the BE DAI is triggered before > the FE DAI. And this order remains the same irrespective of the > trigger command. > > In the case of the SOF driver, during playback, the FW > expects the BE DAI to be triggered before the FE DAI during > the START trigger. The BE DAI trigger handles the starting of > Link DMA and so it must be started before the FE DAI is started > to prevent xruns during pause/release. This can be addressed > by setting the trigger order for the FE dai link to > SND_SOC_DPCM_TRIGGER_POST. But during the STOP trigger, > the FW expects the FE DAI to be triggered before the BE DAI. > Retaining the same order during the START and STOP commands, > results in FW error as the DAI component in the FW is still > active. > > The issue can be fixed by mirroring the trigger order of > FE and BE DAI's during the START and STOP trigger. So, with the > trigger order set to SND_SOC_DPCM_TRIGGER_PRE, the FE DAI will be > trigger first during SNDRV_PCM_TRIGGER_START/STOP/RESUME > and the BE DAI will be triggered first during the > STOP/SUSPEND/PAUSE commands. Conversely, with the trigger order > set to SND_SOC_DPCM_TRIGGER_POST, the BE DAI will be triggered > first during the SNDRV_PCM_TRIGGER_START/STOP/RESUME commands > and the FE DAI will be triggered first during the > SNDRV_PCM_TRIGGER_STOP/SUSPEND/PAUSE commands. > > My first thought was to use a BESPOKE trigger for the SOF driver > but looking more into the implementation of the bespoke trigger > in soc_pcm_bespoke_trigger() didnt indicate it had much to do > with the ordering of the FE/BE DAI's but rather just use the > bespoke trigger callbacks in the DAI driver. > > More details on the SOF issue can be found in: > Github Issue: https://github.com/thesofproject/linux/issues/1160 I am a bit confused because that GitHub link does not provide any test results, and the PR1277 CI results show only half of the platforms tested. not sure why. I also don't get if this is an issue specific to the HDaudio Link DMA or if this is a across-the-board issue. The other comment is that I see quite a few legacy Intel machine drivers with the POST trigger hard-coded for front-ends, and we'd need to retest some of these platforms to see if this change broke them. > > Ranjani Sridharan (2): > ASoC: pcm: update FE/BE trigger order based on the command > ASoC: SOF: topology: set trigger order for FE DAI link > > sound/soc/soc-pcm.c | 99 +++++++++++++++++++++++++++++----------- > sound/soc/sof/topology.c | 4 ++ > 2 files changed, 76 insertions(+), 27 deletions(-) >
Currently, the trigger orders SND_SOC_DPCM_TRIGGER_PRE/POST determine the order in which FE DAI and BE DAI are triggered. In the case of SND_SOC_DPCM_TRIGGER_PRE, the FE DAI is triggered before the BE DAI and in the case of SND_SOC_DPCM_TRIGGER_POST, the BE DAI is triggered before the FE DAI. And this order remains the same irrespective of the trigger command. In the case of the SOF driver, during playback, the FW expects the BE DAI to be triggered before the FE DAI during the START trigger. The BE DAI trigger handles the starting of Link DMA and so it must be started before the FE DAI is started to prevent xruns during pause/release. This can be addressed by setting the trigger order for the FE dai link to SND_SOC_DPCM_TRIGGER_POST. But during the STOP trigger, the FW expects the FE DAI to be triggered before the BE DAI. Retaining the same order during the START and STOP commands, results in FW error as the DAI component in the FW is still active. The issue can be fixed by mirroring the trigger order of FE and BE DAI's during the START and STOP trigger. So, with the trigger order set to SND_SOC_DPCM_TRIGGER_PRE, the FE DAI will be trigger first during SNDRV_PCM_TRIGGER_START/STOP/RESUME and the BE DAI will be triggered first during the STOP/SUSPEND/PAUSE commands. Conversely, with the trigger order set to SND_SOC_DPCM_TRIGGER_POST, the BE DAI will be triggered first during the SNDRV_PCM_TRIGGER_START/STOP/RESUME commands and the FE DAI will be triggered first during the SNDRV_PCM_TRIGGER_STOP/SUSPEND/PAUSE commands. My first thought was to use a BESPOKE trigger for the SOF driver but looking more into the implementation of the bespoke trigger in soc_pcm_bespoke_trigger() didnt indicate it had much to do with the ordering of the FE/BE DAI's but rather just use the bespoke trigger callbacks in the DAI driver. More details on the SOF issue can be found in: Github Issue: https://github.com/thesofproject/linux/issues/1160 Ranjani Sridharan (2): ASoC: pcm: update FE/BE trigger order based on the command ASoC: SOF: topology: set trigger order for FE DAI link sound/soc/soc-pcm.c | 99 +++++++++++++++++++++++++++++----------- sound/soc/sof/topology.c | 4 ++ 2 files changed, 76 insertions(+), 27 deletions(-)