diff options
Diffstat (limited to 'drivers/gpu/drm/i915/i915_gem_tiling.c')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_gem_tiling.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c b/drivers/gpu/drm/i915/i915_gem_tiling.c index 861223bf3944..1a9306665987 100644 --- a/drivers/gpu/drm/i915/i915_gem_tiling.c +++ b/drivers/gpu/drm/i915/i915_gem_tiling.c @@ -93,8 +93,23 @@ i915_gem_detect_bit_6_swizzle(struct drm_device *dev) uint32_t swizzle_y = I915_BIT_6_SWIZZLE_UNKNOWN; if (INTEL_INFO(dev)->gen >= 6) { - swizzle_x = I915_BIT_6_SWIZZLE_NONE; - swizzle_y = I915_BIT_6_SWIZZLE_NONE; + uint32_t dimm_c0, dimm_c1; + dimm_c0 = I915_READ(MAD_DIMM_C0); + dimm_c1 = I915_READ(MAD_DIMM_C1); + dimm_c0 &= MAD_DIMM_A_SIZE_MASK | MAD_DIMM_B_SIZE_MASK; + dimm_c1 &= MAD_DIMM_A_SIZE_MASK | MAD_DIMM_B_SIZE_MASK; + /* Enable swizzling when the channels are populated with + * identically sized dimms. We don't need to check the 3rd + * channel because no cpu with gpu attached ships in that + * configuration. Also, swizzling only makes sense for 2 + * channels anyway. */ + if (dimm_c0 == dimm_c1) { + swizzle_x = I915_BIT_6_SWIZZLE_9_10; + swizzle_y = I915_BIT_6_SWIZZLE_9; + } else { + swizzle_x = I915_BIT_6_SWIZZLE_NONE; + swizzle_y = I915_BIT_6_SWIZZLE_NONE; + } } else if (IS_GEN5(dev)) { /* On Ironlake whatever DRAM config, GPU always do * same swizzling setup. |
