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 @@ do_gmbus_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int num) 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; }