> Date: Wed, 19 Mar 2008 18:10:43 -0400
> From: alexdeucher@gmail.com
> To: lreid@cs.okstate.edu
> CC: dri-users@lists.sourceforge.net
> Subject: Re: [Dri-users] Visual artifacts on radeon 9500 dri
>
> On Tue, Mar 18, 2008 at 9:45 AM, Reid Linnemann <lreid@cs.okstate.edu> wrote:
> > Written by Alex Deucher on 03/18/08 08:39>>
> >
> >
> > > On Tue, Mar 18, 2008 at 9:02 AM, Reid Linnemann <lreid@cs.okstate.edu> wrote:
> > >> Written by Alex Deucher on 03/17/08 08:18>>
> > >> > On Mon, Mar 17, 2008 at 9:08 AM, Reid Linnemann <lreid@cs.okstate.edu> wrote:
> > >> >> Written by Alex Deucher on 03/16/08 19:55>>
> > >> >> > On Sun, Mar 16, 2008 at 8:49 PM, Reid Linnemann <lreid@cs.okstate.edu> wrote:
> > >> >> >> Jerome Glisse wrote:
> > >> >> >> > On Sat, 15 Mar 2008 11:00:25 -0500
> > >> >> >> > Reid Linnemann <lreid@cs.okstate.edu> wrote:
> > >> >> >> >
> > >> >> >> >> Hi list, this is my first time posting and I'm not subscribed.
> > >> >> >> >>
> > >> >> >> >> I'm running Xorg 7.3 with dri on FreeBSD 7-STABLE.
> > >> >> >> >>
> > >> >> >> >> Some time ago I noticed that seemingly random pixels were not being
> > >> >> >> >> rendered in all GL contexts, and simply chalked it up to my card aging.
> > >> >> >> >> But after a while it started to irk me, and then I remembered something
> > >> >> >> >> about my sapphire 9500 - it's got one of the chips with 8 pipelines but
> > >> >> >> >> only 4 enabled, presumably a 9700 that didn't pass QA and was rebadged
> > >> >> >> >> as a 9500. At one time this card was on a Windows box, and I tried
> > >> >> >> >> enabling all 8 pipelines with the softmod, and got the checkerboard
> > >> >> >> >> pattern that indicated this.
> > >> >> >> >>
> > >> >> >> >> With this in mind, I took 10 dumps of a glxgears window and merged them
> > >> >> >> >> together in a multilayer image in gimp, alternating multiply/divide, and
> > >> >> >> >> overlaid a 16x16 grid. The artifacting lined up perfectly in the
> > >> >> >> >> checkerboard pattern. I'm now pretty convinced that somehow either my
> > >> >> >> >> system's DRM module, DRI, or radeon driver are erroneously enabling all
> > >> >> >> >> 8 pipelines on the card, resulting in mooky-stink rendering. Anyone have
> > >> >> >> >> any thoughts on this?
> > >> >> >> >>
> > >> >> >> >> I've attached the images with and without the overlaid grid for reference.
> > >> >> >> >>
> > >> >> >> >>
> > >> >> >> >
> > >> >> >> >>From memory code which detect card model and decide how many
> > >> >> >> > pipe to enable is wrong for many card. We were just optimistic.
> > >> >> >> >
> > >> >> >> > Cheers,
> > >> >> >> > Jerome Glisse <glisse@freedesktop.org>
> > >> >> >>
> > >> >> >> I'd be fine if I knew what code initialized the pipelines, then I might
> > >> >> >> be able to alter it to my needs.
> > >> >> >>
> > >> >> >
> > >> >> > search for R300_GB_TILE_PIPE_COUNT in r300_state.c
> > >> >> >
> > >> >> > Alex
> > >> >>
> > >> >> FWIW I've tried changing the value of this constant from 3<<1 (or 6) to
> > >> >> 2<<1 (or 4), but the bad tiles persist - only unrendered to. They just
> > >> >> appear as flickering holes in the gl context in the same checkerboard
> > >> >> pattern. Does that mean anything to you?
> > >> >
> > >> > The only valid values for pipe count (bits 3:1) for r3xx chips are 0
> > >> > (RV3xx chips - 1 pipe) and 3 (R3xx chips - 2 pipes). The
> > >> > documentation for these chips are available here:
> > >> > http://ati.amd.com/developer/open_gpu_documentation/R3xx_3D_Registers.pdf
> > >> > http://ati.amd.com/developer/open_gpu_documentation/R5xx_Acceleration_v1.2.pdf
> > >> >
> > >> > In your case I suspect you want 0.
> > >> >
> > >> > Alex
> > >>
> > >> That was the ticket. Defining R300_GB_TILE_COUNT as 0 in r300_reg.h
> > >> fixed the tiling issue. Huzzah!
> > >>
> > >
> > > Hey, send me your pci ids so I can push the fix upstream.
> > >
> > > Alex
> >
> > pciconf -lv output:
>
> fix pushed to mesa: 65c4ced1ccea7ff88123296b7f0587faa6f23eef

Wouldn't it be better, now that we have those register docs, to get the number of working pipes from the card itself (specifically GB_PIPE_SELECT) rather than using a list of PCI ids?

--AWJ--


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