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-rw-r--r--drivers/gpu/drm/i915/i915_reg.h4
-rw-r--r--drivers/gpu/drm/i915/intel_i2c.c40
2 files changed, 44 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index fb05849eabab..41285bec8fc0 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -3859,6 +3859,9 @@ enum {
#define PWM2_GATING_DIS (1 << 14)
#define PWM1_GATING_DIS (1 << 13)
+#define GEN9_CLKGATE_DIS_4 _MMIO(0x4653C)
+#define BXT_GMBUS_GATING_DIS (1 << 14)
+
#define _CLKGATE_DIS_PSL_A 0x46520
#define _CLKGATE_DIS_PSL_B 0x46524
#define _CLKGATE_DIS_PSL_C 0x46528
@@ -7557,6 +7560,7 @@ enum {
#define FDI_RX_CHICKEN(pipe) _MMIO_PIPE(pipe, _FDI_RXA_CHICKEN, _FDI_RXB_CHICKEN)
#define SOUTH_DSPCLK_GATE_D _MMIO(0xc2020)
+#define PCH_GMBUSUNIT_CLOCK_GATE_DISABLE (1<<31)
#define PCH_DPLUNIT_CLOCK_GATE_DISABLE (1<<30)
#define PCH_DPLSUNIT_CLOCK_GATE_DISABLE (1<<29)
#define PCH_CPUNIT_CLOCK_GATE_DISABLE (1<<14)
diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c
index a8c08994f505..ef9f91a0b0c9 100644
--- a/drivers/gpu/drm/i915/intel_i2c.c
+++ b/drivers/gpu/drm/i915/intel_i2c.c
@@ -142,6 +142,32 @@ static void pnv_gmbus_clock_gating(struct drm_i915_private *dev_priv,
I915_WRITE(DSPCLK_GATE_D, val);
}
+static void pch_gmbus_clock_gating(struct drm_i915_private *dev_priv,
+ bool enable)
+{
+ u32 val;
+
+ val = I915_READ(SOUTH_DSPCLK_GATE_D);
+ if (!enable)
+ val |= PCH_GMBUSUNIT_CLOCK_GATE_DISABLE;
+ else
+ val &= ~PCH_GMBUSUNIT_CLOCK_GATE_DISABLE;
+ I915_WRITE(SOUTH_DSPCLK_GATE_D, val);
+}
+
+static void bxt_gmbus_clock_gating(struct drm_i915_private *dev_priv,
+ bool enable)
+{
+ u32 val;
+
+ val = I915_READ(GEN9_CLKGATE_DIS_4);
+ if (!enable)
+ val |= BXT_GMBUS_GATING_DIS;
+ else
+ val &= ~BXT_GMBUS_GATING_DIS;
+ I915_WRITE(GEN9_CLKGATE_DIS_4, val);
+}
+
static u32 get_reserved(struct intel_gmbus *bus)
{
struct drm_i915_private *dev_priv = bus->dev_priv;
@@ -484,6 +510,13 @@ do_gmbus_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int num)
int i = 0, inc, try = 0;
int ret = 0;
+ /* Display WA #0868: skl,bxt,kbl,cfl,glk,cnl */
+ if (IS_GEN9_LP(dev_priv))
+ bxt_gmbus_clock_gating(dev_priv, false);
+ else if (HAS_PCH_SPT(dev_priv) ||
+ HAS_PCH_KBP(dev_priv) || HAS_PCH_CNP(dev_priv))
+ pch_gmbus_clock_gating(dev_priv, false);
+
retry:
I915_WRITE_FW(GMBUS0, bus->reg0);
@@ -585,6 +618,13 @@ timeout:
ret = -EAGAIN;
out:
+ /* Display WA #0868: skl,bxt,kbl,cfl,glk,cnl */
+ if (IS_GEN9_LP(dev_priv))
+ bxt_gmbus_clock_gating(dev_priv, true);
+ else if (HAS_PCH_SPT(dev_priv) ||
+ HAS_PCH_KBP(dev_priv) || HAS_PCH_CNP(dev_priv))
+ pch_gmbus_clock_gating(dev_priv, true);
+
return ret;
}