From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Apparently setting up a bunch of GT registers before we've properly
initialized the rest of the GT hardware leads to these setting being
lost. So looks like I broke HSW with commit b7048ea12fbb ("drm/i915:
Do .init_clock_gating() earlier to avoid it clobbering watermarks")
by doing init_clock_gating() too early. This should actually affect
other platforms as well, but apparently not to such a great degree.
What I was ultimately after in that commit was to move the
ilk_init_lp_watermarks() call earlier. So let's undo the damage and
move init_clock_gating() back to where it was, and call
ilk_init_lp_watermarks() just before the watermark state readout.
This highlights how fragile and messed up our init order really is.
I wonder why we even initialize the display before gem. The opposite
order would make much more sense to me...
REVERT THE REVERT, just do the ilk_init_lp_watermarks() motion.
---
drivers/gpu/drm/i915/intel_display.c | 1 +
drivers/gpu/drm/i915/intel_pm.c | 40 ++++++++++++++++--------------------
2 files changed, 19 insertions(+), 22 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 737de251d0f8..bd198bd3e10d 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3676,6 +3676,7 @@ void intel_finish_reset(struct drm_i915_private *dev_priv)
intel_pps_unlock_regs_wa(dev_priv);
intel_modeset_init_hw(dev);
+ intel_init_clock_gating(dev_priv);
spin_lock_irq(&dev_priv->irq_lock);
if (dev_priv->display.hpd_irq_setup)
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 07118c0b69d3..352a6739ed70 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -5754,12 +5754,30 @@ void vlv_wm_sanitize(struct drm_i915_private *dev_priv)
mutex_unlock(&dev_priv->wm.wm_mutex);
}
+/*
+ * FIXME should probably kill this and improve
+ * the real watermark readout/sanitation instead
+ */
+static void ilk_init_lp_watermarks(struct drm_i915_private *dev_priv)
+{
+ 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.
+ */
+}
+
void ilk_wm_get_hw_state(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = to_i915(dev);
struct ilk_wm_values *hw = &dev_priv->wm.hw;
struct drm_crtc *crtc;
+ ilk_init_lp_watermarks(dev_priv);
+
for_each_crtc(dev, crtc)
ilk_pipe_wm_get_hw_state(crtc);
@@ -8213,18 +8231,6 @@ static void g4x_disable_trickle_feed(struct drm_i915_private *dev_priv)
}
}
-static void ilk_init_lp_watermarks(struct drm_i915_private *dev_priv)
-{
- 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 ilk_init_clock_gating(struct drm_i915_private *dev_priv)
{
uint32_t dspclk_gate = ILK_VRHUNIT_CLOCK_GATE_DISABLE;
@@ -8258,8 +8264,6 @@ static void ilk_init_clock_gating(struct drm_i915_private *dev_priv)
(I915_READ(DISP_ARB_CTL) |
DISP_FBC_WM_DIS));
- ilk_init_lp_watermarks(dev_priv);
-
/*
* Based on the document from hardware guys the following bits
* should be set unconditionally in order to enable FBC.
@@ -8372,8 +8376,6 @@ static void gen6_init_clock_gating(struct drm_i915_private *dev_priv)
I915_WRITE(GEN6_GT_MODE,
_MASKED_FIELD(GEN6_WIZ_HASHING_MASK, GEN6_WIZ_HASHING_16x4));
- ilk_init_lp_watermarks(dev_priv);
-
I915_WRITE(CACHE_MODE_0,
_MASKED_BIT_DISABLE(CM0_STC_EVICT_DISABLE_LRA_SNB));
@@ -8600,8 +8602,6 @@ static void bdw_init_clock_gating(struct drm_i915_private *dev_priv)
I915_GTT_PAGE_SIZE_2M);
enum pipe pipe;
- ilk_init_lp_watermarks(dev_priv);
-
/* WaSwitchSolVfFArbitrationPriority:bdw */
I915_WRITE(GAM_ECOCHK, I915_READ(GAM_ECOCHK) | HSW_ECOCHK_ARB_PRIO_SOL);
@@ -8652,8 +8652,6 @@ static void bdw_init_clock_gating(struct drm_i915_private *dev_priv)
static void hsw_init_clock_gating(struct drm_i915_private *dev_priv)
{
- ilk_init_lp_watermarks(dev_priv);
-
/* L3 caching of data atomics doesn't work -- disable it. */
I915_WRITE(HSW_SCRATCH1, HSW_SCRATCH1_L3_DATA_ATOMICS_DISABLE);
I915_WRITE(HSW_ROW_CHICKEN3,
@@ -8708,8 +8706,6 @@ static void ivb_init_clock_gating(struct drm_i915_private *dev_priv)
{
uint32_t snpcr;
- ilk_init_lp_watermarks(dev_priv);
-
I915_WRITE(ILK_DSPCLK_GATE_D, ILK_VRHUNIT_CLOCK_GATE_DISABLE);
/* WaDisableEarlyCull:ivb */
--
2.15.0
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