Re: kernel error with drm

[maya%netbsd.org@localhost]

On Mon, Dec 10, 2018 at 09:26:03PM +0700, Robert Elz wrote:
>     Date:        Sat, 8 Dec 2018 17:38:05 +0000
>     From:        Arthur Barlow <arthurbarlow%gmail.com@localhost>
>     Message-ID:  <CANR6Wa5u22CLN+8ecnmVyXH9wZnm3invc=ka5ji6tfNZJRJCNQ%mail.gmail.com@localhost>
> 
>   | I have noticed periodically that I get and error in my xconsole that reads:
>   | kern error: [drm:(/usr/src/sys/external/bsd/drm2/dist/drm/i915/intel_sprite.c:132)intel_pipe_update_start] *ERROR* Potential atomic update failure on pipe A: -35
> 
> I see this as well, from time to time.   It doesn't seem to affect anything.
> 
> I do get occasional graphics glitches, most often in seamonkey, or
> vncviewer) but they clear up on any redraw ... as best I can tell the
> two are unrelated.

Hmm, I personally enabled triple buffering in the xf86 driver.
I checked it again and it looks like the expectation by developers
is to use a compositor (compiz/wayland/xfwm/kwin...)

That makes sense. It should save a lot of redrawing if we do the
buffering on a per-window basis, but a driver can't offer that.