Re: [PATCH alsa-lib 3/4] pcm: hw: introduce SNDRV_PCM_INFO_PERFECT_DRAIN

[Takashi Iwai <tiwai@suse.de>]

On Thu, 04 May 2023 10:31:50 +0200,
Jaroslav Kysela wrote:
> 
> On 04. 05. 23 10:18, Takashi Iwai wrote:
> > On Tue, 02 May 2023 13:50:09 +0200,
> > Jaroslav Kysela wrote:
> >> 
> >> The driver may not require to touch the sample stream
> >> for the drain operation at all. Handle this situation
> >> in alsa-lib.
> >> 
> >> Signed-off-by: Jaroslav Kysela <perex@perex.cz>
> > 
> > Ideally speaking, the checks and the setups of those new bits should
> > be coupled with the PCM protocol version check (and the version
> > bump).
> > 
> > But it seems that you've already applied the series, and practically
> > seen, those bits should be either not set or harmless, so let's cross
> > fingers.
> 
> Exactly, the current kernel code should skip those new flags, so they
> are used in alsa-lib only. It's just something like a "reservation"
> for the kernel space until things are really used there. We can bump
> the protocol version later (perhaps with other changes).

If you'd like to include the new drain stuff in ALSA 1.2.9 release, we
can take the uapi change to 6.4-rc1, too.  But then let's bump the PCM
protocol version along with it.

So, if you think it's worth aligning with 6.4-rc1, let me know ASAP.
I planned the submission to Linus in tomorrow, and I'd need to prepare
and merge the uapi updates soon.


thanks,

Takashi