[Mesa-dev] [PATCH 01/10] radeonsi: simplify computation of tessellation offchip buffers

[Marek Olšák]

From: Marek Olšák <marek.olsak at amd.com>

This is overly cautious, but better safe than sorry.
---
 src/gallium/drivers/radeonsi/si_state_shaders.c | 17 ++---------------
 1 file changed, 2 insertions(+), 15 deletions(-)

diff --git a/src/gallium/drivers/radeonsi/si_state_shaders.c b/src/gallium/drivers/radeonsi/si_state_shaders.c
index f1170be..619ad9f 100644
--- a/src/gallium/drivers/radeonsi/si_state_shaders.c
+++ b/src/gallium/drivers/radeonsi/si_state_shaders.c
@@ -2935,51 +2935,38 @@ static bool si_update_spi_tmpring_size(struct si_context *sctx)
 		si_mark_atom_dirty(sctx, &sctx->scratch_state);
 	}
 	return true;
 }
 
 static void si_init_tess_factor_ring(struct si_context *sctx)
 {
 	bool double_offchip_buffers = sctx->b.chip_class >= CIK &&
 				      sctx->b.family != CHIP_CARRIZO &&
 				      sctx->b.family != CHIP_STONEY;
-	unsigned max_offchip_buffers_per_se = double_offchip_buffers ? 128 : 64;
+	/* This must be one less than the maximum number due to a hw limitation. */
+	unsigned max_offchip_buffers_per_se = double_offchip_buffers ? 127 : 63;
 	unsigned max_offchip_buffers = max_offchip_buffers_per_se *
 				       sctx->screen->b.info.max_se;
 	unsigned offchip_granularity;
 
 	switch (sctx->screen->tess_offchip_block_dw_size) {
 	default:
 		assert(0);
 		/* fall through */
 	case 8192:
 		offchip_granularity = V_03093C_X_8K_DWORDS;
 		break;
 	case 4096:
 		offchip_granularity = V_03093C_X_4K_DWORDS;
 		break;
 	}
 
-	switch (sctx->b.chip_class) {
-	case SI:
-		max_offchip_buffers = MIN2(max_offchip_buffers, 126);
-		break;
-	case CIK:
-	case VI:
-	case GFX9:
-		max_offchip_buffers = MIN2(max_offchip_buffers, 508);
-		break;
-	default:
-		assert(0);
-		return;
-	}
-
 	assert(!sctx->tf_ring);
 	/* Use 64K alignment for both rings, so that we can pass the address
 	 * to shaders as one SGPR containing bits [16:47].
 	 */
 	sctx->tf_ring = r600_aligned_buffer_create(sctx->b.b.screen,
 						   R600_RESOURCE_FLAG_UNMAPPABLE,
 						   PIPE_USAGE_DEFAULT,
 						   32768 * sctx->screen->b.info.max_se,
 						   64 * 1024);
 	if (!sctx->tf_ring)
-- 
2.7.4