[PATCH] ALSA: hda/i915 - avoid hung task timeout in i915 wait

[Takashi Iwai]

On Tue, 08 Mar 2022 17:29:21 +0100,
Amadeusz SX2awiX4ski wrote:
> 
> On 3/8/2022 3:11 PM, Kai Vehmanen wrote:
> > If kernel is built with hung task detection enabled and
> > CONFIG_DEFAULT_HUNG_TASK_TIMEOUT set to less than 60 seconds,
> > snd_hdac_i915_init() will trigger the hung task timeout in case i915 is
> > not available and taint the kernel.
> >
> > Split the 60sec wait into a loop of smaller waits to avoid this.
> >
> > Cc: Lucas De Marchi <lucas.demarchi at intel.com>
> > Co-developed-by: Ramalingam C <ramalingam.c at intel.com>
> > Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
> > Signed-off-by: Kai Vehmanen <kai.vehmanen at linux.intel.com>
> > ---
> >   sound/hda/hdac_i915.c | 10 ++++++----
> >   1 file changed, 6 insertions(+), 4 deletions(-)
> >
> > diff --git a/sound/hda/hdac_i915.c b/sound/hda/hdac_i915.c
> > index 454474ac5716..6219de739b56 100644
> > --- a/sound/hda/hdac_i915.c
> > +++ b/sound/hda/hdac_i915.c
> > @@ -143,7 +143,8 @@ static bool i915_gfx_present(void)
> >   int snd_hdac_i915_init(struct hdac_bus *bus)
> >   {
> >   	struct drm_audio_component *acomp;
> > -	int err;
> > +	unsigned long wait = 0;
> 
> I'm not sure if it is best name for variable that is set to 0
> ("false"), maybe `done` would be better? Especially looking at
> condition in the following for loop.

Or, more simply some thing like

			/* max 60s timeout */
			for (i = 0; i < 60; i++) {
				if (wait_for_completion_timeout(&acomp->master_bind_complete,
								   msecs_to_jiffies(1000)))
					break;
			}


Takashi