[mutter/wip/texture-purge-on-nvidia: 26/66] renderer/native: Fallback to non-planar API if gbm_bo_get_handle_for_plane fails

[Ray Strode <halfline src gnome org>]

commit 735a75006f65bf4bc862462aa2fdc8f24f110850
Author: Alex Villacís Lasso <a_villacis palosanto com>
Date:   Fri Jul 27 16:08:52 2018 +0000

    renderer/native: Fallback to non-planar API if gbm_bo_get_handle_for_plane fails
    
    Commit c0d9b08ef9bf2be865aad9bf1bc74ba24c655d9f replaced the old GBM API calls
    with the multi-plane GBM API. However, the call to gbm_bo_get_handle_for_plane
    fails for some DRI drivers (in particular i915). Due to missing error checks,
    the subsequent call to drmModeAddFB[2] fails and the screen output locks up.
    
    This commit adds the missing error checks and falls back to the old GBM API
    (non-planar) if necessary.
    
    v5: test success of gbm_bo_get_handle_for_plane instead of errno
    
    This commit adopts solution proposed by Daniel van Vugt to check the return
    value of gbm_bo_get_handle_for_plane on plane 0 and fall back to old
    non-planar method if the call fails. This removes the errno check (for
    ENOSYS) that could abort if mesa ever sets a different value.
    
    Related to: https://gitlab.gnome.org/GNOME/mutter/issues/127
    
    (cherry picked from commit f7af32a3eaefabbea3ebbda3a93eff98dd105ab9)

 src/backends/native/meta-renderer-native.c | 21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)
---
diff --git a/src/backends/native/meta-renderer-native.c b/src/backends/native/meta-renderer-native.c
index 8dc0da710..250a6b6c1 100644
--- a/src/backends/native/meta-renderer-native.c
+++ b/src/backends/native/meta-renderer-native.c
@@ -1607,12 +1607,23 @@ gbm_get_next_fb_id (MetaGpuKms         *gpu_kms,
       return FALSE;
     }
 
-  for (i = 0; i < gbm_bo_get_plane_count (next_bo); i++)
+  if (gbm_bo_get_handle_for_plane (next_bo, 0).s32 == -1)
     {
-      strides[i] = gbm_bo_get_stride_for_plane (next_bo, i);
-      handles[i] = gbm_bo_get_handle_for_plane (next_bo, i).u32;
-      offsets[i] = gbm_bo_get_offset (next_bo, i);
-      modifiers[i] = gbm_bo_get_modifier (next_bo);
+      /* Failed to fetch handle to plane, falling back to old method */
+      strides[0] = gbm_bo_get_stride (next_bo);
+      handles[0] = gbm_bo_get_handle (next_bo).u32;
+      offsets[0] = 0;
+      modifiers[0] = DRM_FORMAT_MOD_INVALID;
+    }
+  else
+    {
+      for (i = 0; i < gbm_bo_get_plane_count (next_bo); i++)
+        {
+          strides[i] = gbm_bo_get_stride_for_plane (next_bo, i);
+          handles[i] = gbm_bo_get_handle_for_plane (next_bo, i).u32;
+          offsets[i] = gbm_bo_get_offset (next_bo, i);
+          modifiers[i] = gbm_bo_get_modifier (next_bo);
+        }
     }
 
   kms_fd = meta_gpu_kms_get_fd (gpu_kms);