On Thu, 23 Sep 2021 18:04:25 +0200, Thomas Gleixner wrote: > > The hrtimer callback pcsp_do_timer() prepares rearming of the timer with > hrtimer_forward(). hrtimer_forward() is intended to provide a mechanism to > forward the expiry time of the hrtimer by a multiple of the period argument > so that the expiry time greater than the time provided in the 'now' > argument. > > pcsp_do_timer() invokes hrtimer_forward() with the current timer expiry > time as 'now' argument. That's providing a periodic timer expiry, but is > not really robust when the timer callback is delayed so that the resulting > new expiry time is already in the past which causes the callback to be > invoked immediately again. If the timer is delayed then the back to back > invocation is not really making it better than skipping the missed > periods. Sound is distorted in any case. > > Use hrtimer_forward_now() which ensures that the next expiry is in the > future. This prevents hogging the CPU in the timer expiry code and allows > later on to remove hrtimer_forward() from the public interfaces. > > Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Cc: alsa-devel@xxxxxxxxxxxxxxxx > Cc: Takashi Iwai <tiwai@xxxxxxxx> > Cc: Jaroslav Kysela <perex@xxxxxxxx> Thanks, applied now to sound git tree. Takashi
