drm/nv50: add more 0x100c80 flushy magic

Fixes the !vbo_fifo path in the 3D driver on certain chipsets.  Still not
really any good idea of what exactly the magic achieves, but it makes
things work.

While we're at it, in the PCIEGART path, flush on unbinding also.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_sgdma.c b/drivers/gpu/drm/nouveau/nouveau_sgdma.c
index ed1590577b6c..554fb45730c1 100644
--- a/drivers/gpu/drm/nouveau/nouveau_sgdma.c
+++ b/drivers/gpu/drm/nouveau/nouveau_sgdma.c
@@ -171,6 +171,24 @@ nouveau_sgdma_unbind(struct ttm_backend *be)
         }
         dev_priv->engine.instmem.finish_access(nvbe->dev);
 
+        if (dev_priv->card_type == NV_50) {
+                nv_wr32(dev, 0x100c80, 0x00050001);
+                if (!nv_wait(0x100c80, 0x00000001, 0x00000000)) {
+                        NV_ERROR(dev, "timeout: (0x100c80 & 1) == 0 (2)\n");
+                        NV_ERROR(dev, "0x100c80 = 0x%08x\n",
+                                                nv_rd32(dev, 0x100c80));
+                        return -EBUSY;
+                }
+
+                nv_wr32(dev, 0x100c80, 0x00000001);
+                if (!nv_wait(0x100c80, 0x00000001, 0x00000000)) {
+                        NV_ERROR(dev, "timeout: (0x100c80 & 1) == 0 (2)\n");
+                        NV_ERROR(dev, "0x100c80 = 0x%08x\n",
+                                                nv_rd32(dev, 0x100c80));
+                        return -EBUSY;
+                }
+        }
+
         nvbe->bound = false;
         return 0;
 }