On 7/30/2018 9:20 PM, Mark Brown wrote:
On Mon, Jul 30, 2018 at 05:32:21PM +0200, Takashi Iwai wrote:
That said, if delay callback of CPU dai provides the additional delay, the patch does correct thing. OTOH, if CPU dai provides the base delay instead, we need to clarify that it's rather a must; the delay calculation in pointer callback becomes bogus in this scenario.
Part of the theory here is that every component might have a delay independently of the rest and we need to add them all together to figure out what the system as a whole will see. Personally I'd rather just have everything use a callack consistently to avoid confusion.
For consistency we can add a delay callback in snd_pcm_ops and modify the drivers which directly assigning runtime->delay to use the callback. Apart from the 2 drivers mentioned in commit message I also found sound/usb to be doing the same and its delay getting lost.
Thanks, Akshu