drm/i915: Disable LP1+ watermarks safely in init

ILK doesn't like if we just write the LP1+ watermarks registers with 0.
We need to just disable the watermarks by clearing the enable bit. Use
that method also when disabling LP1+ watermarks in init_clock_gating.

It looks like disabling the sprite LP1 watermarks can cause underruns
even if we just toggle the WM1S_LP_EN bit. So treat that bit like the
actual watermark numbers and avoid setting it to 0 immediately.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This commit is contained in:
Ville Syrjälä 2013-12-05 15:51:37 +02:00 committed by Daniel Vetter
parent ce0e0713a6
commit 017636cc09

View file

@ -5051,6 +5051,20 @@ static void g4x_disable_trickle_feed(struct drm_device *dev)
}
}
static void ilk_init_lp_watermarks(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
I915_WRITE(WM3_LP_ILK, I915_READ(WM3_LP_ILK) & ~WM1_LP_SR_EN);
I915_WRITE(WM2_LP_ILK, I915_READ(WM2_LP_ILK) & ~WM1_LP_SR_EN);
I915_WRITE(WM1_LP_ILK, I915_READ(WM1_LP_ILK) & ~WM1_LP_SR_EN);
/*
* Don't touch WM1S_LP_EN here.
* Doing so could cause underruns.
*/
}
static void ironlake_init_clock_gating(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
@ -5084,9 +5098,8 @@ static void ironlake_init_clock_gating(struct drm_device *dev)
I915_WRITE(DISP_ARB_CTL,
(I915_READ(DISP_ARB_CTL) |
DISP_FBC_WM_DIS));
I915_WRITE(WM3_LP_ILK, 0);
I915_WRITE(WM2_LP_ILK, 0);
I915_WRITE(WM1_LP_ILK, 0);
ilk_init_lp_watermarks(dev);
/*
* Based on the document from hardware guys the following bits
@ -5193,9 +5206,7 @@ static void gen6_init_clock_gating(struct drm_device *dev)
I915_WRITE(GEN6_GT_MODE,
_MASKED_BIT_ENABLE(GEN6_TD_FOUR_ROW_DISPATCH_DISABLE));
I915_WRITE(WM3_LP_ILK, 0);
I915_WRITE(WM2_LP_ILK, 0);
I915_WRITE(WM1_LP_ILK, 0);
ilk_init_lp_watermarks(dev);
I915_WRITE(CACHE_MODE_0,
_MASKED_BIT_DISABLE(CM0_STC_EVICT_DISABLE_LRA_SNB));
@ -5369,9 +5380,7 @@ static void haswell_init_clock_gating(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
I915_WRITE(WM3_LP_ILK, 0);
I915_WRITE(WM2_LP_ILK, 0);
I915_WRITE(WM1_LP_ILK, 0);
ilk_init_lp_watermarks(dev);
/* According to the spec, bit 13 (RCZUNIT) must be set on IVB.
* This implements the WaDisableRCZUnitClockGating:hsw workaround.
@ -5420,9 +5429,7 @@ static void ivybridge_init_clock_gating(struct drm_device *dev)
struct drm_i915_private *dev_priv = dev->dev_private;
uint32_t snpcr;
I915_WRITE(WM3_LP_ILK, 0);
I915_WRITE(WM2_LP_ILK, 0);
I915_WRITE(WM1_LP_ILK, 0);
ilk_init_lp_watermarks(dev);
I915_WRITE(ILK_DSPCLK_GATE_D, ILK_VRHUNIT_CLOCK_GATE_DISABLE);