[Mesa-dev] [PATCH 1/2] r600g: Do colorformat endian swap for PIPE_USAGE_STAGING

[Oded Gabbay]

There is an old if statement (dated to 2011) that prevented doing
endian swap for colorformat, in case the buffer is marked
as PIPE_USAGE_STAGING.

This is now wrong because st_ReadPixels() reads into a destination
texture that is marked with PIPE_USAGE_STAGING. Therefore, even if
the texture is rendered correctly to the monitor, when reading it
back we get unswapped/wrong values.

This patch makes the check_rgba() function in gl-1.0-readpixsanity
piglit test pass in big-endian.

Signed-off-by: Oded Gabbay <oded.gabbay at gmail.com>
Cc: "11.1 11.2" <mesa-stable at lists.freedesktop.org>
---
 src/gallium/drivers/r600/evergreen_state.c | 13 ++-----------
 src/gallium/drivers/r600/r600_state.c      |  6 +-----
 2 files changed, 3 insertions(+), 16 deletions(-)

diff --git a/src/gallium/drivers/r600/evergreen_state.c b/src/gallium/drivers/r600/evergreen_state.c
index a12638a..47ca7ce 100644
--- a/src/gallium/drivers/r600/evergreen_state.c
+++ b/src/gallium/drivers/r600/evergreen_state.c
@@ -989,12 +989,7 @@ void evergreen_init_color_surface_rat(struct r600_context *rctx,
 		MAX2(64, rctx->screen->b.info.pipe_interleave_bytes / block_size);
 	unsigned pitch = align(pipe_buffer->width0, pitch_alignment);
 
-	/* XXX: This is copied from evergreen_init_color_surface().  I don't
-	 * know why this is necessary.
-	 */
-	if (pipe_buffer->usage == PIPE_USAGE_STAGING) {
-		endian = ENDIAN_NONE;
-	}
+	endian = r600_colorformat_endian_swap(format);
 
 	surf->cb_color_base = r600_resource(pipe_buffer)->gpu_address >> 8;
 
@@ -1146,11 +1141,7 @@ void evergreen_init_color_surface(struct r600_context *rctx,
 	swap = r600_translate_colorswap(surf->base.format);
 	assert(swap != ~0);
 
-	if (rtex->resource.b.b.usage == PIPE_USAGE_STAGING) {
-		endian = ENDIAN_NONE;
-	} else {
-		endian = r600_colorformat_endian_swap(format);
-	}
+	endian = r600_colorformat_endian_swap(format);
 
 	/* blend clamp should be set for all NORM/SRGB types */
 	if (ntype == V_028C70_NUMBER_UNORM || ntype == V_028C70_NUMBER_SNORM ||
diff --git a/src/gallium/drivers/r600/r600_state.c b/src/gallium/drivers/r600/r600_state.c
index f60e304..f902619 100644
--- a/src/gallium/drivers/r600/r600_state.c
+++ b/src/gallium/drivers/r600/r600_state.c
@@ -930,11 +930,7 @@ static void r600_init_color_surface(struct r600_context *rctx,
 	swap = r600_translate_colorswap(surf->base.format);
 	assert(swap != ~0);
 
-	if (rtex->resource.b.b.usage == PIPE_USAGE_STAGING) {
-		endian = ENDIAN_NONE;
-	} else {
-		endian = r600_colorformat_endian_swap(format);
-	}
+	endian = r600_colorformat_endian_swap(format);
 
 	/* set blend bypass according to docs if SINT/UINT or
 	   8/24 COLOR variants */
-- 
2.5.0