fdo-mirrors/mesa
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/mesa/mesa.git synced 2026-05-07 09:18:04 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions 4

i965: Bind null render targets for shadow sampling + color.

Browse source 
Portal 2 appears to bind RGBA8888_UNORM textures to a sampler2DShadow,
and calls shadow2D() on it.  This causes undefined behavior in OpenGL.

Unfortunately, our sampler appears to hang in this scenario, which is
not acceptable.  Just give them a null surface instead, which returns
all zeroes.

Fixes GPU hangs in Portal 2 on Kabylake.

Huge thanks to Jason Ekstrand for noticing this crazy behavior while
sifting through crash dumps.

Cc: mesa-stable@lists.freedesktop.org
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104487
Reviewed-by: Topi Pohjolainen <topi.pohjolainen@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
This commit is contained in:
Kenneth Graunke 2018-01-17 14:16:04 -08:00
parent 7ec6e4e689
commit 3e18c53e59
1 changed files with 32 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

33
src/mesa/drivers/dri/i965/brw_wm_surface_state.c
View file

@ -1095,6 +1095,14 @@ const struct brw_tracked_state brw_renderbuffer_read_surfaces = {
.emit = update_renderbuffer_read_surfaces,
};
static bool
is_depth_texture(struct intel_texture_object *iobj)
{
GLenum base_format = _mesa_get_format_base_format(iobj->_Format);
return base_format == GL_DEPTH_COMPONENT ||
(base_format == GL_DEPTH_STENCIL && !iobj->base.StencilSampling);
}
static void
update_stage_texture_surfaces(struct brw_context *brw,
const struct gl_program *prog,
@ -1121,9 +1129,32 @@ update_stage_texture_surfaces(struct brw_context *brw,
if (prog->SamplersUsed & (1 << s)) {
const unsigned unit = prog->SamplerUnits[s];
const bool used_by_txf = prog->info.textures_used_by_txf & (1 << s);
struct gl_texture_object *obj = ctx->Texture.Unit[unit]._Current;
struct intel_texture_object *iobj = intel_texture_object(obj);
/* _NEW_TEXTURE */
if (ctx->Texture.Unit[unit]._Current) {
if (!obj)
continue;
if ((prog->ShadowSamplers & (1 << s)) && !is_depth_texture(iobj)) {
/* A programming note for the sample_c message says:
*
* "The Surface Format of the associated surface must be
* indicated as supporting shadow mapping as indicated in the
* surface format table."
*
* Accessing non-depth textures via a sampler*Shadow type is
* undefined. GLSL 4.50 page 162 says:
*
* "If a shadow texture call is made to a sampler that does not
* represent a depth texture, then results are undefined."
*
* We give them a null surface (zeros) for undefined. We've seen
* GPU hangs with color buffers and sample_c, so we try and avoid
* those with this hack.
*/
emit_null_surface_state(brw, NULL, surf_offset + s);
} else {
brw_update_texture_surface(ctx, unit, surf_offset + s, for_gather,
used_by_txf, plane);
}