Commit aa02d7e8 authored by Jason Ekstrand's avatar Jason Ekstrand

Revert "anv/skylake: disable ForceThreadDispatchEnable"

This reverts commit 0fa9e6d7.  The real
issue appears to have been that HiZ ops don't like having WM thread
dispatch force-enabled.  The previous commit fixes that problem so we
can go back to using the ForceThreadDispatchEnable bit even on SKL+.

Cc: mesa-stable@lists.freedesktop.org
Reviewed-by: 's avatarKenneth Graunke <kenneth@whitecape.org>
parent b6b2b278
......@@ -1445,12 +1445,12 @@ emit_3dstate_wm(struct anv_pipeline *pipeline, struct anv_subpass *subpass,
wm.EarlyDepthStencilControl = EDSC_NORMAL;
}
#if GEN_GEN == 8
/* Gen8 and later hardware tries to compute ThreadDispatchEnable for
* us but doesn't take into account KillPixels when no depth or
* stencil writes are enabled. In order for occlusion queries to
* work correctly with no attachments, we need to force-enable PS
* thread dispatch.
#if GEN_GEN >= 8
/* Gen8 hardware tries to compute ThreadDispatchEnable for us but
* doesn't take into account KillPixels when no depth or stencil
* writes are enabled. In order for occlusion queries to work
* correctly with no attachments, we need to force-enable PS thread
* dispatch.
*
* The BDW docs are pretty clear that that this bit isn't validated
* and probably shouldn't be used in production:
......@@ -1460,9 +1460,7 @@ emit_3dstate_wm(struct anv_pipeline *pipeline, struct anv_subpass *subpass,
*
* Unfortunately, however, the other mechanism we have for doing this
* is 3DSTATE_PS_EXTRA::PixelShaderHasUAV which causes hangs on BDW.
* Given two bad options, we choose the one which works. On Skylake
* and later, setting ForceThreadDispatchEnable causes GPU hangs so
* we use the PixelShaderHasUAV mechanism there.
* Given two bad options, we choose the one which works.
*/
if ((wm_prog_data->has_side_effects || wm_prog_data->uses_kill) &&
!has_color_buffer_write_enabled(pipeline, blend))
......@@ -1665,32 +1663,6 @@ emit_3dstate_ps_extra(struct anv_pipeline *pipeline,
wm_prog_data->uses_kill;
#if GEN_GEN >= 9
/* Gen8 and later hardware tries to compute ThreadDispatchEnable for us
* but doesn't take into account KillPixels when no depth or stencil
* writes are enabled. In order for occlusion queries to work correctly
* with no attachments, we need to force-enable PS thread dispatch.
*
* The stricter cross-primitive coherency guarantees that the hardware
* gives us with the "Accesses UAV" bit set for at least one shader stage
* and the "UAV coherency required" bit set on the 3DPRIMITIVE command are
* redundant within the current image, atomic counter and SSBO GL and
* Vulkan APIs, which all have very loose ordering and coherency
* requirements and generally rely on the application to insert explicit
* barriers when a shader invocation is expected to see the memory
* writes performed by the invocations of some previous primitive.
* Regardless of the value of "UAV coherency required", the "Accesses
* UAV" bits will implicitly cause an in most cases useless DC flush
* when the lowermost stage with the bit set finishes execution.
*
* Unfortunately, however, the other mechanism we have for doing this is
* 3DSTATE_WM::ForceThreadDispatchEnable which causes GPU hangs on
* Skylake and later hardware. On Broadwell, however, setting this bit
* causes GPU hangs so we use ForceThreadDispatchEnable there.
*/
if ((wm_prog_data->has_side_effects || wm_prog_data->uses_kill) &&
!has_color_buffer_write_enabled(pipeline, blend))
ps.PixelShaderHasUAV = true;
ps.PixelShaderComputesStencil = wm_prog_data->computed_stencil;
ps.PixelShaderPullsBary = wm_prog_data->pulls_bary;
......
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