Nouveau - Feb 2021 - [PATCH 2/3] drm/nouveau/kms/nv50-: Report max cursor size to userspace

Ilia Mirkin, Tue, Feb 23, 2021 16:46:52 +0100:
> On Tue, Feb 23, 2021 at 10:36 AM Alex Riesen <alexander.riesen at
cetitec.com> wrote:
> > Ilia Mirkin, Tue, Feb 23, 2021 15:56:21 +0100:
> > > On Tue, Feb 23, 2021 at 9:26 AM Alex Riesen <alexander.riesen
at cetitec.com> wrote:
> > > >
> > > > This change broke X cursor in my setup, and reverting the
commit restores it.
> > > >
> > > > Dell Precision M4800, issue ~2014 with GK106GLM [Quadro
K2100M] (rev a1).
> > > > libdrm 2.4.91-1 (Debian 10.8 stable).
> > > > There are no errors or warnings in Xorg logs nor in the
kernel log.
> > >
> > > Could you confirm which ddx is driving the nvidia hw? You can
find
> > > this out by running "xrandr --listproviders", or also
in the xorg log.
> >
> > xrandr(1) does not seem to list much:
> >
> > $ xrandr --listproviders
> > Providers: number : 1
> > Provider 0: id: 0x48 cap: 0xf, Source Output, Sink Output, Source
Offload, Sink Offload crtcs: 4 outputs: 5 associated providers: 0
name:modesetting
> 
> Thanks - this is what I was looking for. name:modesetting, i.e. the
> modesetting ddx driver.
> 
> I checked nouveau source, and it seems like it uses a 64x64 cursor no
> matter what. Not sure what the modesetting ddx does.
> 
> I'd recommend using xf86-video-nouveau in any case, but some distros
I would like try this out. Do you know how to force the xorg server to
choose this driver instead of modesetting?
> have decided to explicitly force modesetting in preference of nouveau.
> Oh well. (And regardless, the regression should be addressed somehow,
> but it's also good to understand what the problem is.)
>
> Can you confirm what the problem with the cursor is?
The cursor looks stretched vertically over a bigger matrix, while missing some
lines and being wrapped over the bottom on top of that matrix.

Alex Riesen, Tue, Feb 23, 2021 16:51:26 +0100:
> Ilia Mirkin, Tue, Feb 23, 2021 16:46:52 +0100:
> > I'd recommend using xf86-video-nouveau in any case, but some
distros
> 
> I would like try this out. Do you know how to force the xorg server to
> choose this driver instead of modesetting?
Found that myself (a Device section with Driver set to "nouveau"):

    $ xrandr  --listproviders
    Providers: number : 1
    Provider 0: id: 0x68 cap: 0x7, Source Output, Sink Output, Source Offload
crtcs: 4 outputs: 5 associated providers: 0 name:nouveau

And yes, the cursor looks good in v5.11 even without reverting the commit.