Re: [PATCH 0/2] ALSA: pcm: trace selection process of hardware parameters

[Takashi Iwai <tiwai@suse.de>]

On Fri, 09 Jun 2017 14:46:47 +0200,
Takashi Sakamoto wrote:
> 
> Hi,
> 
> This patchset is a revised version of my former RFC.
> 
> [alsa-devel] [PATCH RFC 00/21] ALSA: pcm: add tracepoints for PCM params operation
> http://mailman.alsa-project.org/pipermail/alsa-devel/2017-May/120548.html
> 
> Unlike SNDRV_PCM_IOCTL_HW_REFINE, returned data from invocation of
> ioctl(2) with SNDRV_PCM_IOCTL_HW_PARAMS includes single value for below
> parameters:
> 
>  * SNDRV_PCM_HW_PARAM_ACCESS
>  * SNDRV_PCM_HW_PARAM_FORMAT
>  * SNDRV_PCM_HW_PARAM_SUBFORMAT
>  * SNDRV_PCM_HW_PARAM_CHANNELS
>  * SNDRV_PCM_HW_PARAM_RATE
>  * SNDRV_PCM_HW_PARAM_PERIOD_TIME
>  * SNDRV_PCM_HW_PARAM_BUFFER_SIZE
>  * SNDRV_PCM_HW_PARAM_TICK_TIME
> 
> This is an additional selection process of hardware parameters in service
> routine of the command.
> 
> This patchset adds tracepoint events to probe the selection process so
> that developers can realize final set of parameters by tracing data.
> 
> Below is a sample. The first three entries are final applications of
> constraint rules. The rest is newly added by this patchset.
> 
> $ trace-cmd report
> ...
> hw_interval_param: pcmC0D0p 021/023 PERIOD_SIZE 0 1 [1000 1000] 0 1 [1000 1000]
> hw_interval_param: pcmC0D0p 022/023 BUFFER_BYTES 0 1 [8000 8000] 0 1 [8000 8000]
> hw_interval_param: pcmC0D0p 023/023 RATE 0 1 [8000 8000] 0 1 [8000 8000]
> hw_mask_param:     pcmC0D0p 000/023 ACCESS 00000000000000000000000000000001 00000000000000000000000000000001
> hw_mask_param:     pcmC0D0p 000/023 FORMAT 00000000000000000000000000000004 00000000000000000000000000000004
> hw_mask_param:     pcmC0D0p 000/023 SUBFORMAT 00000000000000000000000000000001 00000000000000000000000000000001
> hw_interval_param: pcmC0D0p 000/023 CHANNELS 0 1 [1 1] 0 1 [1 1]
> hw_interval_param: pcmC0D0p 000/023 RATE 0 1 [8000 8000] 0 1 [8000 8000]
> hw_interval_param: pcmC0D0p 000/023 PERIOD_TIME 0 1 [125000 125000] 0 1 [125000 125000]
> hw_interval_param: pcmC0D0p 000/023 BUFFER_SIZE 0 1 [4000 4000] 0 1 [4000 4000]
> hw_interval_param: pcmC0D0p 000/023 TICK_TIME 0 1 [0 0] 0 1 [0 0]
> 
> Takashi Sakamoto (3):
>   ALSA: pcm: localize snd_pcm_hw_params_choose()
>   ALSA: pcm: add tracepoints for final selection process of hardware
>     parameters
>   ALSA: pcm: use friendly name for id of PCM substream in trace print

Applied all three patches (although the cover letter says two :)


thanks,

Takashi