Screen corruption using radeon kernel driver

[Alex Deucher]

On Tue, Nov 29, 2022 at 10:59 AM Mikhail Krylov <sqarert at gmail.com> wrote:
>
> On Tue, Nov 29, 2022 at 09:44:19AM -0500, Alex Deucher wrote:
> > On Mon, Nov 28, 2022 at 3:48 PM Mikhail Krylov <sqarert at gmail.com> wrote:
> > >
> > > On Mon, Nov 28, 2022 at 09:50:50AM -0500, Alex Deucher wrote:
> > >
> > > >>> [excessive quoting removed]
> > >
> > > >> So, is there any progress on this issue? I do understand it's not a high
> > > >> priority one, and today I've checked it on 6.0 kernel, and
> > > >> unfortunately, it still persists...
> > > >>
> > > >> I'm considering writing a patch that will allow user to override
> > > >> need_dma32/dma_bits setting with a module parameter. I'll have some time
> > > >> after the New Year for that.
> > > >>
> > > >> Is it at all possible that such a patch will be merged into kernel?
> > > >>
> > > > On Mon, Nov 28, 2022 at 9:31 AM Mikhail Krylov <sqarert at gmail.com> wrote:
> > > > Unless someone familiar with HIMEM can figure out what is going wrong
> > > > we should just revert the patch.
> > > >
> > > > Alex
> > >
> > >
> > > Okay, I was suggesting that mostly because
> > >
> > > a) it works for me with dma_bits = 40 (I understand that's what it is
> > > without the original patch applied);
> > >
> > > b) there's a hint of uncertainity on this line
> > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/gpu/drm/radeon/radeon_device.c#n1359
> > > saying that for AGP dma_bits = 32 is the safest option, so apparently there are
> > > setups, unlike mine, where dma_bits = 32 is better than 40.
> > >
> > > But I'm in no position to argue, just wanted to make myself clear.
> > > I'm okay with rebuilding the kernel for my machine until the original
> > > patch is reverted or any other fix is applied.
> >
> > What GPU do you have and is it AGP?  If it is AGP, does setting
> > radeon.agpmode=-1 also fix it?
> >
> > Alex
>
> That is ATI Radeon X1950, and, unfortunately, radeon.agpmode=-1 doesn't
> help, it just makes 3D acceleration in games such as OpenArena stop
> working.

Just to confirm, is the board AGP or PCIe?

Alex