[Mesa-dev] [PATCH] 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>
---
 src/gallium/drivers/radeonsi/si_descriptors.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/src/gallium/drivers/radeonsi/si_descriptors.c b/src/gallium/drivers/radeonsi/si_descriptors.c
index 71f4d71..d66996a 100644
--- a/src/gallium/drivers/radeonsi/si_descriptors.c
+++ b/src/gallium/drivers/radeonsi/si_descriptors.c
@@ -512,6 +512,23 @@ 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_image(struct si_context *ctx,
 				struct si_images_info *images,
 				unsigned slot, struct pipe_image_view *view)
@@ -533,6 +550,9 @@ static void si_set_shader_image(struct si_context *ctx,
 				   RADEON_USAGE_READWRITE);
 
 	if (res->b.b.target == PIPE_BUFFER) {
+		if (view->access & PIPE_IMAGE_ACCESS_WRITE)
+			si_mark_image_range_valid(view);
+
 		si_make_buffer_descriptor(screen, res,
 					  view->format,
 					  view->u.buf.first_element,
@@ -1361,6 +1381,9 @@ 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