[alsa-devel] [PATCH alsa-lib] pcm: dmix: Handle slave PCM xrun and unexpected states properly

[Alexander E. Patrakov]

30.10.2015 21:33, Alexander E. Patrakov wrote:
> [resending to the list, sorry for the duplicate]
>
> 30.10.2015 21:18, Takashi Iwai wrote:
>> Currently, dmix & co plugins ignore the XRUN state of the slave PCM.
>> It's (supposedly) because dmix deals with the PCM in a free-wheel
>> mode, which is equivalent with XRUN.  But, this difference (whether
>> the correct freewheel or XRUN) should be done by the kernel, and we
>> may have an XRUN state indeed (e.g. via xrun injection).
>>
>> This patch fixes this lack of behavior, to handle PCM xrun and does
>> prepare when the slave PCM is in such a state.
>>
>> Also, the patch consolidates the prepare callback for all dmix, dsnoop
>> and dshare plugins, and fix/cleanup a bit for dshare/dsnoop codes to
>> align with dsnoop code.
>>
>> Signed-off-by: Takashi Iwai <tiwai at suse.de>
>
> Just a nitpick.
>
> In snd_pcm_direct_prepare(), you use snd_pcm_state(...) directly in the
> switch statement, but in other places of the patch you introduce a
> temporary variable for the state. Why?

Sorry for the noise - you do need a temporary variable, because you 
return its value.

>
> Also, in snd_pcm_direct_prepare(), the "dmix" variable name is confusing.
>

So, other than that, the patch looks OK.

-- 
Alexander E. Patrakov