drm/nv50: add a memory barrier to pushbuf submission
authorMaarten Maathuis <madman2003@gmail.com>
Thu, 25 Feb 2010 19:00:38 +0000 (20:00 +0100)
committerBen Skeggs <bskeggs@redhat.com>
Wed, 10 Mar 2010 06:07:35 +0000 (16:07 +1000)
- This is useful for vram pushbuffers that are write combined.
- pre-nv50 has one too (in WRITE_PUT).

Signed-off-by: Maarten Maathuis <madman2003@gmail.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
drivers/gpu/drm/nouveau/nouveau_dma.c

index c8482a108a7801c321875ecbf5ff4e041563d3e9..65c441a1999facfeeb3b9ca191198fad732583d8 100644 (file)
@@ -190,6 +190,11 @@ nv50_dma_push(struct nouveau_channel *chan, struct nouveau_bo *bo,
        nouveau_bo_wr32(pb, ip++, upper_32_bits(offset) | length << 8);
 
        chan->dma.ib_put = (chan->dma.ib_put + 1) & chan->dma.ib_max;
+
+       DRM_MEMORYBARRIER();
+       /* Flush writes. */
+       nouveau_bo_rd32(pb, 0);
+
        nvchan_wr32(chan, 0x8c, chan->dma.ib_put);
        chan->dma.ib_free--;
 }