Re: [Intel-gfx] [PATCH 2/2] hda/i915: split the wait for the component binding

[Takashi Iwai <tiwai@suse.de>]

On Thu, 24 Feb 2022 17:34:54 +0100,
Kai Vehmanen wrote:
> 
> Hi,
> 
> On Thu, 24 Feb 2022, Ramalingam C wrote:
> 
> > Split the wait for component binding from i915 in multiples of
> > sysctl_hung_task_timeout_secs. This helps to avoid the possible kworker
> > thread hung detection given below.
> 
> while I understand the problem, I'm not sure whether a simpler option
> should be chosen. Maybe just split the wait_for_completion_timeout()
> into small 5sec iterations, without consulting value of hung_task_timeout.
> This would seem unligned with more mainstream use of 
> wait_for_completion_timeout() in kernel and still do the job.
> 
> I'll loop in Takashi here as well. Basicly the 60 sec timeout in 
> hda/hdac_i915.c is getting caught by hung_task_detection logic in builds
> where the hung_task_timeout is below 60secs.
> 
> I have a patch that tries to avoid hitting the timeout in some of the more 
> common cases:
> "ALSA: hda/i915 - skip acomp init if no matching display"
> https://lists.freedesktop.org/archives/intel-gfx-trybot/2022-February/128278.html
> ... but we'll still be stuck with some configurations where the timeout 
> will be hit. And above needs careful testing.
> 
> One logic comment below as well, but I'll quote the whole patch to give
> context to Takashi.

I agree with Kai, we can just make the wait_for_completion_timeout()
split in a loop independently from hung_task_timeout.  It's simpler,
less error-prone.


thanks,

Takashi