From a7f014f2de04893f95cfe40fe35f15c8dae4b36e Mon Sep 17 00:00:00 2001 From: Eric Anholt Date: Tue, 25 Nov 2008 14:02:05 -0800 Subject: [PATCH] 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 Signed-off-by: Dave Airlie --- drivers/gpu/drm/i915/i915_gem_tiling.c | 7 ++++--- drivers/gpu/drm/i915/i915_reg.h | 1 + 2 files changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c b/drivers/gpu/drm/i915/i915_gem_tiling.c index e8b85ac4ca04..a8cb69469c64 100644 --- a/drivers/gpu/drm/i915/i915_gem_tiling.c +++ b/drivers/gpu/drm/i915/i915_gem_tiling.c @@ -119,9 +119,10 @@ i915_gem_detect_bit_6_swizzle(struct drm_device *dev) dcc & DCC_CHANNEL_XOR_DISABLE) { swizzle_x = I915_BIT_6_SWIZZLE_9_10; swizzle_y = I915_BIT_6_SWIZZLE_9; - } else if (IS_I965GM(dev) || IS_GM45(dev)) { - /* GM965 only does bit 11-based channel - * randomization + } else if ((IS_I965GM(dev) || IS_GM45(dev)) && + (dcc & DCC_CHANNEL_XOR_BIT_17) == 0) { + /* GM965/GM45 does either bit 11 or bit 17 + * swizzling. */ swizzle_x = I915_BIT_6_SWIZZLE_9_10_11; swizzle_y = I915_BIT_6_SWIZZLE_9_11; diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 0e476eba36e6..9d24aaeb8a45 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 -- 2.20.1