[PATCH xserver] modesetting: Remove ms_crtc_msc_to_kernel_msc().

[Mario Kleiner]

Hi Daniel, Eero,

On Fri, May 4, 2018 at 2:41 PM, Daniel Stone <daniel at fooishbar.org> wrote:
> Hi Mario,
>
> On 4 May 2018 at 13:14, Mario Kleiner <mario.kleiner.de at gmail.com> wrote:
>> Indeed, i found a Mesa bug yesterday which can cause Mesa's
>> PresentPixmap request to spuriously feed garbage targetMSC's
>> into the driver under some conditions. However, while other
>> video drivers seem to cope relatively well with that, modesetting
>> ddx causes KDE-5's plasmashell to lock up badly quite frequently,
>> and my suspicion is that the code removed in this commit is one
>> major source of the extra fragility.
>
> Thanks a lot for tracking this down! Adding Eero to Cc, who I think
> stumbled on this very problem.

You mean the Mesa bug? I'll quickly send out something half finished
for discussion to mesa-devel, cc'ed to xorg-devel, which "fixes" the
bug in two different ways, both are not optimal, but better than
nothing. Lacking this fix, KDE-5 is pretty much unusable due to
frequent lockup on server 1.20 with the modesetting-ddx atm.

-mario

>
> Cheers,
> Daniel