From: Nicolai Hähnle Date: Wed, 3 May 2017 09:26:27 +0000 (+0200) Subject: radeonsi: fix gl_PrimitiveID in tessellation with instanced draws on SI X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=f16b7558632d1d2d355a8251e969b8fc41f9c1e8;p=mesa.git radeonsi: fix gl_PrimitiveID in tessellation with instanced draws on SI Cc: mesa-stable@lists.freedesktop.org Reviewed-by: Marek Olšák --- diff --git a/src/gallium/drivers/radeonsi/si_state_draw.c b/src/gallium/drivers/radeonsi/si_state_draw.c index 5f1371a1433..f0ed898cfb0 100644 --- a/src/gallium/drivers/radeonsi/si_state_draw.c +++ b/src/gallium/drivers/radeonsi/si_state_draw.c @@ -188,6 +188,20 @@ static void si_emit_derived_tess_state(struct si_context *sctx, if (sctx->b.chip_class == SI) { 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 + * should cause IA to split instances up. However, this + * doesn't work correctly on SI when there is no other + * SE to switch to. + */ + *num_patches = 1; + } } sctx->last_num_patches = *num_patches;