[alsa-devel] [PATCH 1/2] ALSA: firewire: process packets in 'struct snd_pcm_ops.ack' callback

[Takashi Sakamoto]

On Jun 9 2017 15:53, Takashi Iwai wrote:
>>> From: Takashi Iwai <tiwai at suse.de>
>>> Subject: [PATCH] ALSA: pcm: Suppress status/control mmap when ack ops is
>>>   present
>>>
>>> The drivers using PCM ack ops require the notification whenever
>>> appl_ptr is updated in general.  But when the PCM status/control page
>>> is mmapped, this notification doesn't happen, per design, thus it's
>>> not guaranteed to receive the fine-grained updates.
>>>
>>> For improving the situation, this patch simply suppresses the PCM
>>> status/control mmap when ack ops is defined.  At least, for all
>>> existing drivers with ack, this should give more benefit.
>>>
>>> Once when we really need the full optimization with status/control
>>> mmap even using ack ops, we may reconsider the check, e.g. introducing
>>> a new flag.  But, so far, this should be good enough.
>>
>> Yes this makes sense and we tested it for us, looks good
>>
>> Reveiwed-by: Vinod Koul <vinod.koul at intel.com>
>> Tested-by: Subhransu S. Prusty <subhransu.s.prusty at intel.com>
> 
> OK, thanks.
> 
> If Sakamato-san is happy with this change, I'm going to merge it for
> 4.13.

I'm writing a long long message about my concern for this patch. I'm 
happy if you postpone application to your for-next branch, till next week.


Thanks

Takashi Sakamoto