Commit eca4a654 authored by Danylo Piliaiev's avatar Danylo Piliaiev Committed by Kenneth Graunke

i965: Disable dual source blending when shader doesn't support it on gen8+

Dual source blending behaviour is undefined when shader doesn't
have second color output, dismissing fragment in such situation
leads to a hang on gen8+ if depth test in enabled.

Since blending cannot be gracefully fixed in such case and the result
is undefined - blending is simply disabled.

v2 (Kenneth Graunke):
 - Listen to BRW_NEW_FS_PROG_DATA in 3DSTATE_PS_BLEND
 - Also whack BLEND_STATE[] to keep the two in sync, since we're not
   sure exactly which copy of the redundant info the hardware will use.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107088Signed-off-by: Danylo Piliaiev's avatarDanylo Piliaiev <danylo.piliaiev@globallogic.com>
Reviewed-by: Jason Ekstrand's avatarJason Ekstrand <jason@jlekstrand.net>
Reviewed-by: Kenneth Graunke's avatarKenneth Graunke <kenneth@whitecape.org>
parent 337a8080
......@@ -3051,7 +3051,26 @@ set_blend_entry_bits(struct brw_context *brw, BLEND_ENTRY_GENXML *entry, int i,
dstA = fix_dual_blend_alpha_to_one(dstA);
}
entry->ColorBufferBlendEnable = true;
/* BRW_NEW_FS_PROG_DATA */
const struct brw_wm_prog_data *wm_prog_data =
brw_wm_prog_data(brw->wm.base.prog_data);
/* The Dual Source Blending documentation says:
*
* "If SRC1 is included in a src/dst blend factor and
* a DualSource RT Write message is not used, results
* are UNDEFINED. (This reflects the same restriction in DX APIs,
* where undefined results are produced if “o1” is not written
* by a PS – there are no default values defined).
* If SRC1 is not included in a src/dst blend factor,
* dual source blending must be disabled."
*
* There is no way to gracefully fix this undefined situation
* so we just disable the blending to prevent possible issues.
*/
entry->ColorBufferBlendEnable =
!ctx->Color.Blend[0]._UsesDualSrc || wm_prog_data->dual_src_blend;
entry->DestinationBlendFactor = blend_factor(dstRGB);
entry->SourceBlendFactor = blend_factor(srcRGB);
entry->DestinationAlphaBlendFactor = blend_factor(dstA);
......@@ -3197,6 +3216,7 @@ static const struct brw_tracked_state genX(blend_state) = {
_NEW_MULTISAMPLE,
.brw = BRW_NEW_BATCH |
BRW_NEW_BLORP |
BRW_NEW_FS_PROG_DATA |
BRW_NEW_STATE_BASE_ADDRESS,
},
.emit = genX(upload_blend_state),
......@@ -4829,7 +4849,25 @@ genX(upload_ps_blend)(struct brw_context *brw)
dstA = fix_dual_blend_alpha_to_one(dstA);
}
pb.ColorBufferBlendEnable = true;
/* BRW_NEW_FS_PROG_DATA */
const struct brw_wm_prog_data *wm_prog_data =
brw_wm_prog_data(brw->wm.base.prog_data);
/* The Dual Source Blending documentation says:
*
* "If SRC1 is included in a src/dst blend factor and
* a DualSource RT Write message is not used, results
* are UNDEFINED. (This reflects the same restriction in DX APIs,
* where undefined results are produced if “o1” is not written
* by a PS – there are no default values defined).
* If SRC1 is not included in a src/dst blend factor,
* dual source blending must be disabled."
*
* There is no way to gracefully fix this undefined situation
* so we just disable the blending to prevent possible issues.
*/
pb.ColorBufferBlendEnable =
!color->Blend[0]._UsesDualSrc || wm_prog_data->dual_src_blend;
pb.SourceAlphaBlendFactor = brw_translate_blend_factor(srcA);
pb.DestinationAlphaBlendFactor = brw_translate_blend_factor(dstA);
pb.SourceBlendFactor = brw_translate_blend_factor(srcRGB);
......@@ -4848,7 +4886,8 @@ static const struct brw_tracked_state genX(ps_blend) = {
_NEW_MULTISAMPLE,
.brw = BRW_NEW_BLORP |
BRW_NEW_CONTEXT |
BRW_NEW_FRAGMENT_PROGRAM,
BRW_NEW_FRAGMENT_PROGRAM |
BRW_NEW_FS_PROG_DATA,
},
.emit = genX(upload_ps_blend)
};
......
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