linux 3.0.8 alsa資料流程分析
ALSA開啟資料流程
soc_pcm_open => cpu_dai->driver->ops->startup => platform->driver->ops->open => codec_dai->driver->ops->startup \
=> rtd->dai_link->ops->startup
ALSA的HW_param流程
soc_pcm_hw_params => rtd->dai_link->ops->hw_params => codec_dai->driver->ops->hw_params => cpu_dai->driver->ops->hw_params \
=> platform->driver->ops->hw_params
ALSA的Prepare流程
snd_pcm_prepare => snd_pcm_action_nonatomic => snd_pcm_action_group => snd_pcm_do_prepare => substream->ops->prepare \
=> soc_pcm_prepare => rtd->dai_link->ops->prepare => platform->driver->ops->prepare => codec_dai->driver->ops->prepare \
=> cpu_dai->driver->ops->prepare
ALSA的Write流程
snd_pcm_playback_ioctl => snd_pcm_playback_ioctl1 => SNDRV_PCM_IOCTL_WRITEN_FRAMES => snd_pcm_lib_writev => snd_pcm_lib_write1 \
=> |||| => snd_pcm_lib_writev_transfer => copy_from_user [copy user speace data to dma]
snd_pcm_start => snd_pcm_action => snd_pcm_action_group => snd_pcm_do_start => substream->ops->trigger
ALSA的Trigger流程
substream->ops->trigger => soc_pcm_trigger => codec_dai->driver->ops->trigger => platform->driver->ops->trigger \
=> cpu_dai->driver->ops->trigger
ALSA的cset流程
snd_ctl_ioctl => SNDRV_CTL_IOCTL_ELEM_WRITE => snd_ctl_elem_write_user => snd_ctl_elem_write => kctl->put => codec->write
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作者:dyron
來源:CSDN
原文:https://blog.csdn.net/dyron/article/details/8154725
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