According to the bspec for MBCTL: Driver must set bit in the following scenarios: - to realod teh h/w boot context every time it gets loaded through OS - after an FLR clears the register (BIOS won't run afterwards) References: https://bugs.freedesktop.org/show_bug.cgi?id=50237 Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org> --- drivers/gpu/drm/i915/intel_pm.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index 4565512..c50d5e4 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -3361,6 +3361,9 @@ static void gen6_init_clock_gating(struct drm_device *dev) ILK_DPARB_CLK_GATE | ILK_DPFD_CLK_GATE); + I915_WRITE(GEN6_MBCTL, I915_READ(GEN6_MBCTL) | + GEN6_MBCTL_ENABLE_BOOT_FETCH); + for_each_pipe(pipe) { I915_WRITE(DSPCNTR(pipe), I915_READ(DSPCNTR(pipe)) | @@ -3438,6 +3441,9 @@ static void ivybridge_init_clock_gating(struct drm_device *dev) intel_flush_display_plane(dev_priv, pipe); } + I915_WRITE(GEN6_MBCTL, I915_READ(GEN6_MBCTL) | + GEN6_MBCTL_ENABLE_BOOT_FETCH); + gen7_setup_fixed_func_scheduler(dev_priv); /* WaDisable4x2SubspanOptimization */ @@ -3476,6 +3482,9 @@ static void valleyview_init_clock_gating(struct drm_device *dev) I915_READ(GEN7_SQ_CHICKEN_MBCUNIT_CONFIG) | GEN7_SQ_CHICKEN_MBCUNIT_SQINTMOB); + I915_WRITE(GEN6_MBCTL, I915_READ(GEN6_MBCTL) | + GEN6_MBCTL_ENABLE_BOOT_FETCH); + /* According to the BSpec vol1g, bit 12 (RCPBUNIT) clock * gating disable must be set. Failure to set it results in -- 1.7.9.5
