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path: root/drivers/gpu/drm/nouveau/nouveau_agp.c
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Diffstat (limited to 'drivers/gpu/drm/nouveau/nouveau_agp.c')
-rw-r--r--drivers/gpu/drm/nouveau/nouveau_agp.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/gpu/drm/nouveau/nouveau_agp.c b/drivers/gpu/drm/nouveau/nouveau_agp.c
index d28430cd2ba6..6e7a55f93a85 100644
--- a/drivers/gpu/drm/nouveau/nouveau_agp.c
+++ b/drivers/gpu/drm/nouveau/nouveau_agp.c
@@ -47,6 +47,18 @@ nouveau_agp_enabled(struct nouveau_drm *drm)
if (drm->agp.stat == UNKNOWN) {
if (!nouveau_agpmode)
return false;
+#ifdef __powerpc__
+ /* Disable AGP by default on all PowerPC machines for
+ * now -- At least some UniNorth-2 AGP bridges are
+ * known to be broken: DMA from the host to the card
+ * works just fine, but writeback from the card to the
+ * host goes straight to memory untranslated bypassing
+ * the GATT somehow, making them quite painful to deal
+ * with...
+ */
+ if (nouveau_agpmode == -1)
+ return false;
+#endif
return true;
}