glamor: Recover gracefully from prepare_access PBO allocation failure.raspbian-backport

We may be allocating big PBOs here, based on the size of the FBO, so
it's a fairly likely place for a driver to OOM.  When it happens, just
fall back to the non-PBO transfer path.

Signed-off-by: Eric Anholt <eric@anholt.net>

1 files changed, 24 insertions, 9 deletions

diff --git a/glamor/glamor_prepare.c b/glamor/glamor_prepare.c
index 4d29bd9de..66eb87522 100644
--- a/glamor/glamor_prepare.c
+++ b/glamor/glamor_prepare.c
@@ -83,16 +83,33 @@ glamor_prep_pixmap_box(PixmapPtr pixmap, glamor_access_t access, BoxPtr box)
         RegionInit(&priv->prepare_region, box, 1);
 
         if (glamor_priv->has_rw_pbo) {
+            GLsizei size = pixmap->devKind * pixmap->drawable.height;
+
             if (priv->pbo == 0)
                 glGenBuffers(1, &priv->pbo);
 
             gl_usage = GL_STREAM_READ;
 
             glBindBuffer(GL_PIXEL_PACK_BUFFER, priv->pbo);
-            glBufferData(GL_PIXEL_PACK_BUFFER,
-                         pixmap->devKind * pixmap->drawable.height, NULL,
-                         gl_usage);
-        } else {
+            glamor_priv->suppress_gl_out_of_memory_logging = TRUE;
+            glBufferData(GL_PIXEL_PACK_BUFFER, size, NULL, gl_usage);
+            glamor_priv->suppress_gl_out_of_memory_logging = FALSE;
+
+            if (glGetError() == GL_OUT_OF_MEMORY) {
+                if (!glamor_priv->logged_any_oom) {
+                    LogMessageVerb(X_WARNING, 0,
+                                   "Failed to allocate %db PBO for fallback "
+                                   "rendering.\n", size);
+                    LogMessageVerb(X_WARNING, 0,
+                                   "Expect reduced performance.\n");
+                    glamor_priv->logged_any_oom = true;
+                }
+                glDeleteBuffers(1, &priv->pbo);
+                priv->pbo = 0;
+            }
+        }
+
+        if (!priv->pbo) {
             pixmap->devPrivate.ptr = malloc(pixmap->devKind *
                                             pixmap->drawable.height);
             if (!pixmap->devPrivate.ptr)
@@ -106,7 +123,7 @@ glamor_prep_pixmap_box(PixmapPtr pixmap, glamor_access_t access, BoxPtr box)
 
     RegionUninit(&region);
 
-    if (glamor_priv->has_rw_pbo) {
+    if (priv->pbo) {
         if (priv->map_access == GLAMOR_ACCESS_RW)
             gl_access = GL_READ_WRITE;
         else
@@ -128,8 +145,6 @@ glamor_prep_pixmap_box(PixmapPtr pixmap, glamor_access_t access, BoxPtr box)
 static void
 glamor_fini_pixmap(PixmapPtr pixmap)
 {
-    ScreenPtr                   screen = pixmap->drawable.pScreen;
-    glamor_screen_private       *glamor_priv = glamor_get_screen_private(screen);
     glamor_pixmap_private       *priv = glamor_get_pixmap_private(pixmap);
 
     if (!GLAMOR_PIXMAP_PRIV_HAS_FBO(priv))
@@ -138,7 +153,7 @@ glamor_fini_pixmap(PixmapPtr pixmap)
     if (!priv->prepared)
         return;
 
-    if (glamor_priv->has_rw_pbo) {
+    if (priv->pbo) {
         glBindBuffer(GL_PIXEL_UNPACK_BUFFER, priv->pbo);
         glUnmapBuffer(GL_PIXEL_UNPACK_BUFFER);
         pixmap->devPrivate.ptr = NULL;
@@ -153,7 +168,7 @@ glamor_fini_pixmap(PixmapPtr pixmap)
 
     RegionUninit(&priv->prepare_region);
 
-    if (glamor_priv->has_rw_pbo) {
+    if (priv->pbo) {
         glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
         glDeleteBuffers(1, &priv->pbo);
         priv->pbo = 0;