[Mesa-dev] [PATCH] intel: Fix a case when mapping large texture fails

[Anuj Phogat]

This patch handles a case when mapping a large texture fails
in drm_intel_gem_bo_map_gtt(). These changes avoid assertion
failure later in the driver as reported in following bugs:

https://bugs.freedesktop.org/show_bug.cgi?id=44970
https://bugs.freedesktop.org/show_bug.cgi?id=46303

Signed-off-by: Anuj Phogat <anuj.phogat at gmail.com>
---
 src/mesa/drivers/dri/intel/intel_mipmap_tree.c |   26 ++++++++++++++++-------
 src/mesa/drivers/dri/intel/intel_regions.c     |    7 ++++-
 2 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/src/mesa/drivers/dri/intel/intel_mipmap_tree.c b/src/mesa/drivers/dri/intel/intel_mipmap_tree.c
index 5290da4..507702a 100644
--- a/src/mesa/drivers/dri/intel/intel_mipmap_tree.c
+++ b/src/mesa/drivers/dri/intel/intel_mipmap_tree.c
@@ -702,15 +702,20 @@ intel_miptree_map_gtt(struct intel_context *intel,
    y /= bh;
 
    base = intel_region_map(intel, mt->region, map->mode);
-   /* Note that in the case of cube maps, the caller must have passed the slice
-    * number referencing the face.
-    */
-   intel_miptree_get_image_offset(mt, level, 0, slice, &image_x, &image_y);
-   x += image_x;
-   y += image_y;
 
-   map->stride = mt->region->pitch * mt->cpp;
-   map->ptr = base + y * map->stride + x * mt->cpp;
+   if (base == NULL)
+      map->ptr = NULL;
+   else {
+      /* Note that in the case of cube maps, the caller must have passed the
+       * slice number referencing the face.
+      */
+      intel_miptree_get_image_offset(mt, level, 0, slice, &image_x, &image_y);
+      x += image_x;
+      y += image_y;
+
+      map->stride = mt->region->pitch * mt->cpp;
+      map->ptr = base + y * map->stride + x * mt->cpp;
+   }
 
    DBG("%s: %d,%d %dx%d from mt %p (%s) %d,%d = %p/%d\n", __FUNCTION__,
        map->x, map->y, map->w, map->h,
@@ -1063,6 +1068,11 @@ intel_miptree_map(struct intel_context *intel,
 
    *out_ptr = map->ptr;
    *out_stride = map->stride;
+
+   if (map->ptr == NULL) {
+      mt->level[level].slice[slice].map = NULL;
+      free(map);
+   }
 }
 
 void
diff --git a/src/mesa/drivers/dri/intel/intel_regions.c b/src/mesa/drivers/dri/intel/intel_regions.c
index bc83649..982d6cb 100644
--- a/src/mesa/drivers/dri/intel/intel_regions.c
+++ b/src/mesa/drivers/dri/intel/intel_regions.c
@@ -124,7 +124,7 @@ intel_region_map(struct intel_context *intel, struct intel_region *region,
     */
 
    _DBG("%s %p\n", __FUNCTION__, region);
-   if (!region->map_refcount++) {
+   if (!region->map_refcount) {
       intel_flush(&intel->ctx);
 
       if (region->tiling != I915_TILING_NONE)
@@ -133,7 +133,10 @@ intel_region_map(struct intel_context *intel, struct intel_region *region,
 	 drm_intel_bo_map(region->bo, true);
 
       region->map = region->bo->virtual;
-      ++intel->num_mapped_regions;
+      if (region->map) {
+         ++intel->num_mapped_regions;
+	 region->map_refcount++;
+      }
    }
 
    return region->map;
-- 
1.7.7.6