[Mesa-dev] [PATCH 1/1] i965: return the fourcc saved in __DRIimage when possible

[James Xiong]

From: "Xiong, James" <james.xiong at intel.com>

When creating a image from a texture, the image's dri_format is
set to the first plane's format, and used to look up for the
fourcc. e.g. for FOURCC_NV12 texture, the dri_format is set to
__DRI_IMAGE_FORMAT_R8, we end up with a wrong entry in function
intel_lookup_fourcc():
   { __DRI_IMAGE_FOURCC_R8, __DRI_IMAGE_COMPONENTS_R, 1,
     { { 0, 0, 0, __DRI_IMAGE_FORMAT_R8, 1 }, } },
instead of the corret one:
   { __DRI_IMAGE_FOURCC_NV12, __DRI_IMAGE_COMPONENTS_Y_UV, 2,
     { { 0, 0, 0, __DRI_IMAGE_FORMAT_R8, 1 },
       { 1, 1, 1, __DRI_IMAGE_FORMAT_GR88, 2 } } },
as a result, a wrong fourcc __DRI_IMAGE_FOURCC_R8 was returned.

To fix this bug, the image inherits the texture's planar_format that
has the original fourcc; Upon querying, if planar_format is set,
return the saved fourcc; Otherwise fall back to the old way.

v3: add a bug description and "cc mesa-stable" tag (Jason)
  remove abandunt null pointer check (Tapani)
  squash 2 patches into one (James)
v2: fall back to intel_lookup_fourcc() when planar_format is NULL
  (Dongwon & Matt Roper)

Cc: mesa-stable at lists.freedesktop.org
Signed-off-by: Xiong, James <james.xiong at intel.com>
---
 src/mesa/drivers/dri/i965/intel_screen.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/intel_screen.c b/src/mesa/drivers/dri/i965/intel_screen.c
index dcb98da..29cb7ad 100644
--- a/src/mesa/drivers/dri/i965/intel_screen.c
+++ b/src/mesa/drivers/dri/i965/intel_screen.c
@@ -388,10 +388,16 @@ intel_image_format_lookup(int fourcc)
    return NULL;
 }
 
-static boolean intel_lookup_fourcc(int dri_format, int *fourcc)
+static boolean
+intel_image_get_fourcc(__DRIimage *image, int *fourcc)
 {
+   if (image->planar_format) {
+      *fourcc = image->planar_format->fourcc;
+      return true;
+   }
+
    for (unsigned i = 0; i < ARRAY_SIZE(intel_image_formats); i++) {
-      if (intel_image_formats[i].planes[0].dri_format == dri_format) {
+      if (intel_image_formats[i].planes[0].dri_format == image->dri_format) {
          *fourcc = intel_image_formats[i].fourcc;
          return true;
       }
@@ -578,6 +584,7 @@ intel_create_image_from_texture(__DRIcontext *context, int target,
    intel_setup_image_from_mipmap_tree(brw, image, iobj->mt, level, zoffset);
    image->dri_format = driGLFormatToImageFormat(image->format);
    image->has_depthstencil = iobj->mt->stencil_mt? true : false;
+   image->planar_format = iobj->planar_format;
    if (image->dri_format == MESA_FORMAT_NONE) {
       *error = __DRI_IMAGE_ERROR_BAD_PARAMETER;
       free(image);
@@ -869,7 +876,7 @@ intel_query_image(__DRIimage *image, int attrib, int *value)
    case __DRI_IMAGE_ATTRIB_FD:
       return !brw_bo_gem_export_to_prime(image->bo, value);
    case __DRI_IMAGE_ATTRIB_FOURCC:
-      return intel_lookup_fourcc(image->dri_format, value);
+      return intel_image_get_fourcc(image, value);
    case __DRI_IMAGE_ATTRIB_NUM_PLANES:
       if (isl_drm_modifier_has_aux(image->modifier)) {
          assert(!image->planar_format || image->planar_format->nplanes == 1);
-- 
2.7.4