[Mesa-dev] [PATCH] radeonsi: Handle NULL sampler views getting passed in by the state tracker.

[Michel Dänzer]

From: Michel Dänzer <michel.daenzer at amd.com>

Don't dereference NULL pointers, and if all views are NULL, don't generate an
invalid PM4 packet which locks up the GPU.

Signed-off-by: Michel Dänzer <michel.daenzer at amd.com>
---
 src/gallium/drivers/radeonsi/radeonsi_pm4.c |    7 +++++++
 src/gallium/drivers/radeonsi/si_state.c     |   12 +++++++-----
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/src/gallium/drivers/radeonsi/radeonsi_pm4.c b/src/gallium/drivers/radeonsi/radeonsi_pm4.c
index 3c53ce2..8268f91 100644
--- a/src/gallium/drivers/radeonsi/radeonsi_pm4.c
+++ b/src/gallium/drivers/radeonsi/radeonsi_pm4.c
@@ -109,6 +109,13 @@ void si_pm4_sh_data_add(struct si_pm4_state *state, uint32_t dw)
 void si_pm4_sh_data_end(struct si_pm4_state *state, unsigned reg)
 {
 	unsigned offs = state->last_pm4 + 1;
+
+	/* Bail if no data was added */
+	if (state->ndw == offs) {
+		state->ndw--;
+		return;
+	}
+
 	si_pm4_cmd_end(state, false);
 
 	si_pm4_cmd_begin(state, PKT3_SET_SH_REG_OFFSET);
diff --git a/src/gallium/drivers/radeonsi/si_state.c b/src/gallium/drivers/radeonsi/si_state.c
index 11acb73..9a9a250 100644
--- a/src/gallium/drivers/radeonsi/si_state.c
+++ b/src/gallium/drivers/radeonsi/si_state.c
@@ -1971,16 +1971,18 @@ static void si_set_ps_sampler_view(struct pipe_context *ctx, unsigned count,
 
 	si_pm4_sh_data_begin(pm4);
 	for (i = 0; i < count; i++) {
-		struct r600_resource_texture *tex = (void *)resource[i]->base.texture;
-
 		pipe_sampler_view_reference(
 			(struct pipe_sampler_view **)&rctx->ps_samplers.views[i],
 			views[i]);
 
-		si_pm4_add_bo(pm4, &tex->resource, RADEON_USAGE_READ);
+		if (views[i]) {
+			struct r600_resource_texture *tex = (void *)resource[i]->base.texture;
+
+			si_pm4_add_bo(pm4, &tex->resource, RADEON_USAGE_READ);
 
-		for (j = 0; j < Elements(resource[i]->state); ++j) {
-			si_pm4_sh_data_add(pm4, resource[i]->state[j]);
+			for (j = 0; j < Elements(resource[i]->state); ++j) {
+				si_pm4_sh_data_add(pm4, resource[i]->state[j]);
+			}
 		}
 	}
 
-- 
1.7.10.4