diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 412b38ab83eb..249addb98a3e 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -2726,6 +2726,9 @@ #define FDI_RXB_CHICKEN 0xc2010 #define FDI_RX_PHASE_SYNC_POINTER_ENABLE (1) +#define SOUTH_DSPCLK_GATE_D 0xc2020 +#define PCH_DPLSUNIT_CLOCK_GATE_DISABLE (1<<29) + /* CPU: FDI_TX */ #define FDI_TXA_CTL 0x60100 #define FDI_TXB_CTL 0x61100 diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 979228594599..e92ba16f7d79 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -5673,6 +5673,13 @@ void intel_init_clock_gating(struct drm_device *dev) I915_WRITE(PCH_DSPCLK_GATE_D, dspclk_gate); + /* + * On Ibex Peak and Cougar Point, we need to disable clock + * gating for the panel power sequencer or it will fail to + * start up when no ports are active. + */ + I915_WRITE(SOUTH_DSPCLK_GATE_D, PCH_DPLSUNIT_CLOCK_GATE_DISABLE); + /* * According to the spec the following bits should be set in * order to enable memory self-refresh