[Sound-open-firmware] [PATCH] sof: Turn IRQs off globally when send command to pipeline component

[zhigang.wu]

On 2018年03月27日 23:37, Pierre-Louis Bossart wrote:
> On 3/27/18 4:17 AM, Wu Zhigang wrote:
>> When pipeline processing the command, we have to turn off the IRQs.
>> If not, the DMA IRQ will interrupt the pipeline state set process,
>> when pipeline is scheduled, the states inconsistence will cause xrun.
>
> we disable the irqs but then will walk the graph from host to DAI with 
> component_op_downstream to pass a COMPS_OPS_CMD with in turn will call 
> all .cmd callbacks from all components
>
> This could take a significant amount of time and lead to interrupts 
> unrelated to that specific pipeline not being serviced, leading to xruns.
>
> what am I missing?
>
This point I also mentioned in the previous email list.
I also worried about the IRQs masked duration might be too long.
My suggestion is change the state set sequence, set the DAI component 
first, then VOL, the last HOST.
Liam's comments is the mask duration is short.
thanks
zhigang.wu

>>
>> Signed-off-by: Wu Zhigang <zhigang.wu at linux.intel.com>
>>
>> ---
>> Tested with
>> apl-gpmrb board
>>
>> kernel: https://github.com/plbossart/sound.git  branch: topic/sof-v4.14
>>     95d77adbaadc44b28c8975a3714f70824d1a8529
>>
>> firmware: git://git.alsa-project.org/sound-open-firmware.git branch: 
>> 1.1-stable
>>          210989dffeea811de2370fccb7cf5d53106b1e6e
>>
>> tools:    branch: 1.1-stable
>>     cc91c73aa3e91eea35abdeb76d578b97f718feff
>> ---
>>   src/audio/pipeline.c | 5 +++--
>>   1 file changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/src/audio/pipeline.c b/src/audio/pipeline.c
>> index 1b7f248..23be503 100644
>> --- a/src/audio/pipeline.c
>> +++ b/src/audio/pipeline.c
>> @@ -627,6 +627,7 @@ int pipeline_cmd(struct pipeline *p, struct 
>> comp_dev *host, int cmd,
>>   {
>>       struct op_data op_data;
>>       int ret;
>> +    uint32_t flags;
>>         trace_pipe("cmd");
>>   @@ -635,7 +636,7 @@ int pipeline_cmd(struct pipeline *p, struct 
>> comp_dev *host, int cmd,
>>       op_data.cmd = cmd;
>>       op_data.cmd_data = data;
>>   -    spin_lock(&p->lock);
>> +    spin_lock_irq(&p->lock, flags);
>>         if (host->params.direction == SOF_IPC_STREAM_PLAYBACK) {
>>           /* send cmd downstream from host to DAI */
>> @@ -651,7 +652,7 @@ int pipeline_cmd(struct pipeline *p, struct 
>> comp_dev *host, int cmd,
>>           trace_error_value(cmd);
>>       }
>>   -    spin_unlock(&p->lock);
>> +    spin_unlock_irq(&p->lock, flags);
>>       return ret;
>>   }
>>
>