From: Nicolai Hähnle <[email protected]>
Limiting LS-HS to a single wave is required on all SI chips due to an
issue with a power management feature.
---
src/gallium/drivers/radeonsi/si_state_draw.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/src/gallium/drivers/radeonsi/si_state_draw.c
b/src/gallium/drivers/radeonsi/si_state_draw.c
index 3d1d1f8..f31d5c2 100644
--- a/src/gallium/drivers/radeonsi/si_state_draw.c
+++ b/src/gallium/drivers/radeonsi/si_state_draw.c
@@ -177,22 +177,24 @@ static void si_emit_derived_tess_state(struct si_context
*sctx,
/* Make sure the output data fits in the offchip buffer */
*num_patches = MIN2(*num_patches,
(sctx->screen->tess_offchip_block_dw_size * 4) /
output_patch_size);
/* Not necessary for correctness, but improves performance. The
* specific value is taken from the proprietary driver.
*/
*num_patches = MIN2(*num_patches, 40);
- /* SI bug workaround - limit LS-HS threadgroups to only one wave. */
if (sctx->b.chip_class == SI) {
+ /* SI bug workaround, related to power management. Limit LS-HS
+ * threadgroups to only one wave.
+ */
unsigned one_wave = 64 / MAX2(num_tcs_input_cp,
num_tcs_output_cp);
*num_patches = MIN2(*num_patches, one_wave);
if (sctx->screen->b.info.max_se == 1) {
/* The VGT HS block increments the patch ID
unconditionally
* within a single threadgroup. This results in
incorrect
* patch IDs when instanced draws are used.
*
* The intended solution is to restrict threadgroups to
* a single instance by setting SWITCH_ON_EOI, which
--
2.9.3
_______________________________________________
mesa-dev mailing list
[email protected]
https://lists.freedesktop.org/mailman/listinfo/mesa-dev
