Re: [RFC PATCH v1 1/1] leds: support to use own workqueue for each LED

From: Pavel Machek
Date: Sun Oct 30 2022 - 16:15:35 EST


Hi!

> >> This allows to set own workqueue for each LED. This may be useful, because
> >> default 'system_wq' does not guarantee execution order of each work_struct,
> >> thus for several brightness update requests (for multiple leds), real
> >> brightness switch could be in random order.
> >
> > So.. what?
> >
> > Even if execution order is switched, human eye will not be able to
> > tell the difference.
> Hello,
>
> Problem arises on one of our boards where we have 14 triples of leds(each
> triple contains R G B). Test case is to play complex animation on all leds:
> smooth switch from on RGB state to another. Sometimes there are glitches in
> this process - divergence from expectable RGB state. We fixed this by using
> ordered workqueue.

Are there other solutions possible? Like batch and always apply _all_
the updates you have queued from your the worker code?

Best regards,
Pavel

--
People of Russia, stop Putin before his war on Ukraine escalates.

Attachment: signature.asc
Description: PGP signature