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

[Alex Riesen]

Ilia Mirkin, Wed, Feb 24, 2021 16:10:57 +0100:
> On Wed, Feb 24, 2021 at 4:09 AM Alex Riesen <alexander.riesen at cetitec.com> wrote:
> > Ilia Mirkin, Tue, Feb 23, 2021 19:13:59 +0100:
> > > It might also be worthwhile just testing if the 256x256 cursor works
> > > quite the way one would want. If you're interested, grab libdrm,
> > > there's a test called 'modetest', which has an option to enable a
> > > moving cursor (-c iirc). It's hard-coded to 64x64, so you'll have to
> > > modify it there too (and probably change the pattern from plain gray
> > > to any one of the other ones).
> >
> > I am interested, so I did.
> >
> > If I start the test without X running, the sprite of 256x256 cursor always
> > contained horizontal lines across it, both with commit reverted and vanilla
> > v5.11. Similarly, the 64x64 cursor has no lines across it in both kernels.
> >
> > The test does not seem to work at all if there is an X server running (using
> > modesetting driver): modetest complained about permission denied to set the
> > mode, and just sits there, drawing nothing on the displays.
> > So I could not run the test in the environment of original problem.
> > Am I starting it correctly? Is the change in modetest.c correct?
> 
> Looks right. Although TBH I'd just start it on a single display (I
> forgot you could even do multiple displays). You should be able to
> start it with the X server running if you switch to a vt (and run it
> as root). If you can't, that means the modesetting driver is
> forgetting to do something in the LeaveVT function.

Tried that and yes, modetest works. Even without running it as root.

> The fact that you're getting lines with modetest means there's
> something wrong with 256x256. What if you do 128x128 -- does that work
> OK?

Yes. Unfortunately in both cases.

> Simon, you tested on a GK208, that has a slightly later display
> controller than the GK104 -- can you try to reproduce Alex's results?
> Perhaps there was a problem with the GK10x's and it starts working OK
> with the GK110 disp.
> 
> I don't have any GK10x's in my posession (I have nearly every other
> iteration of the display controller), but hopefully someone on the
> nouveau team will be able to dig one up and reproduce.
> 
> Thanks for testing, Alex!

You're welcome! As I'm stuck with this particular machine for foreseeable
future, you can count on mine GK10x as well.