From: Ville Syrjälä Date: Tue, 4 Feb 2014 19:59:15 +0000 (+0200) Subject: drm/i915: Fix SNB GT_MODE register setup X-Git-Tag: firefly_0821_release~176^2~3773^2~63^2~332 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=8d85d27281095e4df6eb97ae84326b5814337337;p=firefly-linux-kernel-4.4.55.git drm/i915: Fix SNB GT_MODE register setup On SNB we set up WaSetupGtModeTdRowDispatch:snb early in gen6_init_clock_gating(). That sets a bit in the GEN6_GT_MODE register. However later we go and disable all the bits in the same register. And then we go on to set some other bit. So apparently we never actually implemented this workaround since the "disable all bits" part was there already before the w/a got supposedly implemented. These are the relevant commits: commit 6547fbdbfff62c99e4f7b4f985ff8b3454f33b0f Author: Daniel Vetter Date: Fri Dec 14 23:38:29 2012 +0100 drm/i915: Implement WaSetupGtModeTdRowDispatch commit f8f2ac9a76b0f80a6763ca316116a7bab8486997 Author: Ben Widawsky Date: Wed Oct 3 19:34:24 2012 -0700 drm/i915: Fix GT_MODE default value So, let's drop the "disable all bits" part, move both writes to closer proxomity to each other, and name the WIZ hashing bits appropriately. BSpec is still a bit confused how the bits should actually be interpreted, but I took the the description for the high bit since the low bit part only lists values for a single bit. Also add a comment about our choice of WIZ hashing mode. Signed-off-by: Ville Syrjälä Reviewed-by: Antti Koskipää Signed-off-by: Daniel Vetter --- diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 2f564ce37d2c..071c17d408c8 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -798,7 +798,11 @@ # define ASYNC_FLIP_PERF_DISABLE (1 << 14) #define GEN6_GT_MODE 0x20d0 -#define GEN6_GT_MODE_HI (1 << 9) +#define GEN6_WIZ_HASHING(hi, lo) (((hi) << 9) | ((lo) << 7)) +#define GEN6_WIZ_HASHING_8x8 GEN6_WIZ_HASHING(0, 0) +#define GEN6_WIZ_HASHING_8x4 GEN6_WIZ_HASHING(0, 1) +#define GEN6_WIZ_HASHING_16x4 GEN6_WIZ_HASHING(1, 0) +#define GEN6_WIZ_HASHING_MASK (GEN6_WIZ_HASHING(1, 1) << 16) #define GEN6_TD_FOUR_ROW_DISPATCH_DISABLE (1 << 5) #define GFX_MODE 0x02520 diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index a6b877a4a916..45dd23f12a6f 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -4661,6 +4661,13 @@ static void gen6_init_clock_gating(struct drm_device *dev) I915_WRITE(GEN6_GT_MODE, _MASKED_BIT_ENABLE(GEN6_TD_FOUR_ROW_DISPATCH_DISABLE)); + /* + * BSpec recoomends 8x4 when MSAA is used, + * however in practice 16x4 seems fastest. + */ + I915_WRITE(GEN6_GT_MODE, + GEN6_WIZ_HASHING_MASK | GEN6_WIZ_HASHING_16x4); + ilk_init_lp_watermarks(dev); I915_WRITE(CACHE_MODE_0, @@ -4724,11 +4731,6 @@ static void gen6_init_clock_gating(struct drm_device *dev) g4x_disable_trickle_feed(dev); - /* The default value should be 0x200 according to docs, but the two - * platforms I checked have a 0 for this. (Maybe BIOS overrides?) */ - I915_WRITE(GEN6_GT_MODE, _MASKED_BIT_DISABLE(0xffff)); - I915_WRITE(GEN6_GT_MODE, _MASKED_BIT_ENABLE(GEN6_GT_MODE_HI)); - cpt_init_clock_gating(dev); gen6_check_mch_setup(dev);