drm/i915: Respect GM965/GM45 bit-17-instead-of-bit-11 option for swizzling.
This fixes readpixels and buffer corruption when swapped out and in by
disabling tiling on them.
Now that we know that the bit 17 mode isn't just a mistake of older chipsets,
we'll need to work on a clever fix so that we can get the performance of
tiling on these chipsets, but that will require intrusive changes targeted
at the next kernel release, not this one.
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 0e476eb..9d24aae 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -522,6 +522,7 @@
#define DCC_ADDRESSING_MODE_DUAL_CHANNEL_INTERLEAVED (2 << 0)
#define DCC_ADDRESSING_MODE_MASK (3 << 0)
#define DCC_CHANNEL_XOR_DISABLE (1 << 10)
+#define DCC_CHANNEL_XOR_BIT_17 (1 << 9)
/** 965 MCH register controlling DRAM channel configuration */
#define C0DRB3 0x10206