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<b><a class="bz_bug_link
bz_status_NEW "
title="NEW - GL Excess demo renders incorrectly on nv43"
href="https://bugs.freedesktop.org/show_bug.cgi?id=92306#c14">Comment # 14</a>
on <a class="bz_bug_link
bz_status_NEW "
title="NEW - GL Excess demo renders incorrectly on nv43"
href="https://bugs.freedesktop.org/show_bug.cgi?id=92306">bug 92306</a>
from <span class="vcard"><a class="email" href="mailto:imirkin@alum.mit.edu" title="Ilia Mirkin <imirkin@alum.mit.edu>"> <span class="fn">Ilia Mirkin</span></a>
</span></b>
<pre>(In reply to Andrew Randrianasulu from <a href="show_bug.cgi?id=92306#c13">comment #13</a>)
<span class="quote">> (In reply to Ilia Mirkin from <a href="show_bug.cgi?id=92306#c12">comment #12</a>)
> > (In reply to Andrew Randrianasulu from <a href="show_bug.cgi?id=92306#c11">comment #11</a>)
> > > "Mismatched color and zeta formats, ignoring zeta."
> >
> > Yeah, as I suspected... unfortunately there's not a ton you can do besides
> > fixing the issue. The problem is that you can't render to a 32-bit color
> > format (e.g. RGBA8) while using a 16-bit zeta (Z16), and conversely you
> > can't render to a 16-bit color format (e.g. RGB565) while using a 32-bit
> > zeta (Z24S8).
> >
> > My current solution to this problem is to just not set the zeta buffer and
> > move on with life. This leads to incorrect rendering, but at least no hangs.
> >
> > The proper solution is to have 2 depth textures that you copy to and fro and
> > set the "right" one for the given color format. Ideally while minimizing the
> > number of copies.
>
> Hm, but in my case it apparently worked fine... so, may be check is
> overrestrictive?
>
> I also tried to apply this path on top of mesa version indicated above
> ((git-93161be)
>
> ----patch---
> diff --git a/src/gallium/drivers/nouveau/nv30/nv30_state.c
> b/src/gallium/drivers/nouveau/nv30/nv30_state.c
> index fd604c2..cceedfd 100644
> --- a/src/gallium/drivers/nouveau/nv30/nv30_state.c
> +++ b/src/gallium/drivers/nouveau/nv30/nv30_state.c
> @@ -382,7 +382,7 @@ nv30_set_framebuffer_state(struct pipe_context *pipe,
> (util_format_get_blocksize(fb->zsbuf->format) > 2) !=
> (util_format_get_blocksize(fb->cbufs[0]->format) > 2)) {
> nv30->framebuffer.zsbuf = NULL;
> - debug_printf("Mismatched color and zeta formats, ignoring
> zeta.\n");
> + debug_printf("Mismatched color %d and zeta %d formats, ignoring
> zeta.\n", fb->cbufs[0]->format, fb->zsbuf->format);
> }
> }
> }
> --------end-----
>
> and got this in terminal:
> "Mismatched color 1 and zeta 16 formats, ignoring zeta."
>
> This is a bit strange, this demo from ~2002 era, and apparently was working
> fine on older nvidia hardware. And on nouveau, until this commit. I will
> retest just for making sure it doesn't flood my dmesg with errors ....</span >
You should be seeing errors about invalid values in dmesg for 0208 or some
similar method. I'm guessing that the zeta buffer is used in such a way that
things happen to work out, but the card doesn't really support it.
src/gallium/include/pipe/p_format.h: PIPE_FORMAT_B8G8R8A8_UNORM = 1,
src/gallium/include/pipe/p_format.h: PIPE_FORMAT_Z16_UNORM =
16,
Not a valid combo, AFAIK.</pre>
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