[Mesa-dev] [PATCH (backport)] radeonsi: mark buffer texture range valid for shader images

[Nicolai Hähnle]

From: Nicolai Hähnle <nicolai.haehnle at amd.com>

When a shader image view into a buffer texture can be written to, the buffer's
valid range must be updated, or subsequent transfers may incorrectly skip
synchronization.

This fixes a bug that was exposed in Xephyr by PBO acceleration for glReadPixels,
reported by Michel Dänzer.

Cc: Michel Dänzer <michel.daenzer at amd.com>
Cc: 12.0 <mesa-stable at lists.freedesktop.org>
Reviewed-by: Marek Olšák <marek.olsak at amd.com>

Back-ported from commit a64c7cd2bac33a3a2bf908b5ef538dff03b93b73:
- include util/u_format.h
- code was extracted to si_set_shader_image in master, move it back

Signed-off-by: Nicolai Hähnle <nicolai.haehnle at amd.com>
--
 src/gallium/drivers/radeonsi/si_descriptors.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/src/gallium/drivers/radeonsi/si_descriptors.c b/src/gallium/drivers/radeonsi/si_descriptors.c
index 855b79e..e8ce87b 100644
--- a/src/gallium/drivers/radeonsi/si_descriptors.c
+++ b/src/gallium/drivers/radeonsi/si_descriptors.c
@@ -60,6 +60,7 @@
 #include "si_shader.h"
 #include "sid.h"
 
+#include "util/u_format.h"
 #include "util/u_math.h"
 #include "util/u_memory.h"
 #include "util/u_suballoc.h"
@@ -471,6 +472,23 @@ si_disable_shader_image(struct si_images_info *images, unsigned slot)
 }
 
 static void
+si_mark_image_range_valid(struct pipe_image_view *view)
+{
+	struct r600_resource *res = (struct r600_resource *)view->resource;
+	const struct util_format_description *desc;
+	unsigned stride;
+
+	assert(res && res->b.b.target == PIPE_BUFFER);
+
+	desc = util_format_description(view->format);
+	stride = desc->block.bits / 8;
+
+	util_range_add(&res->valid_buffer_range,
+		       stride * (view->u.buf.first_element),
+		       stride * (view->u.buf.last_element + 1));
+}
+
+static void
 si_set_shader_images(struct pipe_context *pipe, unsigned shader,
 		     unsigned start_slot, unsigned count,
 		     struct pipe_image_view *views)
@@ -502,6 +520,9 @@ si_set_shader_images(struct pipe_context *pipe, unsigned shader,
 					   RADEON_USAGE_READWRITE);
 
 		if (res->b.b.target == PIPE_BUFFER) {
+			if (views[i].access & PIPE_IMAGE_ACCESS_WRITE)
+				si_mark_image_range_valid(&views[i]);
+
 			si_make_buffer_descriptor(screen, res,
 						  views[i].format,
 						  views[i].u.buf.first_element,
@@ -1297,6 +1318,9 @@ static void si_invalidate_buffer(struct pipe_context *ctx, struct pipe_resource
 			unsigned i = u_bit_scan(&mask);
 
 			if (images->views[i].resource == buf) {
+				if (images->views[i].access & PIPE_IMAGE_ACCESS_WRITE)
+					si_mark_image_range_valid(&images->views[i]);
+
 				si_desc_reset_buffer_offset(
 					ctx, images->desc.list + i * 8 + 4,
 					old_va, buf);
-- 
2.7.4