diff options
Diffstat (limited to 'drivers/gpu/drm/i915/intel_display.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_display.c | 83 |
1 files changed, 61 insertions, 22 deletions
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 5e8b91f..0e172ce 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -4701,7 +4701,7 @@ static void ironlake_init_pch_refclk(struct drm_device *dev) struct drm_i915_private *dev_priv = dev->dev_private; struct drm_mode_config *mode_config = &dev->mode_config; struct intel_encoder *encoder; - u32 temp; + u32 val, final; bool has_lvds = false; bool has_cpu_edp = false; bool has_pch_edp = false; @@ -4744,70 +4744,109 @@ static void ironlake_init_pch_refclk(struct drm_device *dev) * PCH B stepping, previous chipset stepping should be * ignoring this setting. */ - temp = I915_READ(PCH_DREF_CONTROL); + val = I915_READ(PCH_DREF_CONTROL); + + /* As we must carefully and slowly disable/enable each source in turn, + * compute the final state we want first and check if we need to + * make any changes at all. + */ + final = val; + final &= ~DREF_NONSPREAD_SOURCE_MASK; + if (has_ck505) + final |= DREF_NONSPREAD_CK505_ENABLE; + else + final |= DREF_NONSPREAD_SOURCE_ENABLE; + + final &= ~DREF_SSC_SOURCE_MASK; + final &= ~DREF_CPU_SOURCE_OUTPUT_MASK; + final &= ~DREF_SSC1_ENABLE; + + if (has_panel) { + final |= DREF_SSC_SOURCE_ENABLE; + + if (intel_panel_use_ssc(dev_priv) && can_ssc) + final |= DREF_SSC1_ENABLE; + + if (has_cpu_edp) { + if (intel_panel_use_ssc(dev_priv) && can_ssc) + final |= DREF_CPU_SOURCE_OUTPUT_DOWNSPREAD; + else + final |= DREF_CPU_SOURCE_OUTPUT_NONSPREAD; + } else + final |= DREF_CPU_SOURCE_OUTPUT_DISABLE; + } else { + final |= DREF_SSC_SOURCE_DISABLE; + final |= DREF_CPU_SOURCE_OUTPUT_DISABLE; + } + + if (final == val) + return; + /* Always enable nonspread source */ - temp &= ~DREF_NONSPREAD_SOURCE_MASK; + val &= ~DREF_NONSPREAD_SOURCE_MASK; if (has_ck505) - temp |= DREF_NONSPREAD_CK505_ENABLE; + val |= DREF_NONSPREAD_CK505_ENABLE; else - temp |= DREF_NONSPREAD_SOURCE_ENABLE; + val |= DREF_NONSPREAD_SOURCE_ENABLE; if (has_panel) { - temp &= ~DREF_SSC_SOURCE_MASK; - temp |= DREF_SSC_SOURCE_ENABLE; + val &= ~DREF_SSC_SOURCE_MASK; + val |= DREF_SSC_SOURCE_ENABLE; /* SSC must be turned on before enabling the CPU output */ if (intel_panel_use_ssc(dev_priv) && can_ssc) { DRM_DEBUG_KMS("Using SSC on panel\n"); - temp |= DREF_SSC1_ENABLE; + val |= DREF_SSC1_ENABLE; } else - temp &= ~DREF_SSC1_ENABLE; + val &= ~DREF_SSC1_ENABLE; /* Get SSC going before enabling the outputs */ - I915_WRITE(PCH_DREF_CONTROL, temp); + I915_WRITE(PCH_DREF_CONTROL, val); POSTING_READ(PCH_DREF_CONTROL); udelay(200); - temp &= ~DREF_CPU_SOURCE_OUTPUT_MASK; + val &= ~DREF_CPU_SOURCE_OUTPUT_MASK; /* Enable CPU source on CPU attached eDP */ if (has_cpu_edp) { if (intel_panel_use_ssc(dev_priv) && can_ssc) { DRM_DEBUG_KMS("Using SSC on eDP\n"); - temp |= DREF_CPU_SOURCE_OUTPUT_DOWNSPREAD; + val |= DREF_CPU_SOURCE_OUTPUT_DOWNSPREAD; } else - temp |= DREF_CPU_SOURCE_OUTPUT_NONSPREAD; + val |= DREF_CPU_SOURCE_OUTPUT_NONSPREAD; } else - temp |= DREF_CPU_SOURCE_OUTPUT_DISABLE; + val |= DREF_CPU_SOURCE_OUTPUT_DISABLE; - I915_WRITE(PCH_DREF_CONTROL, temp); + I915_WRITE(PCH_DREF_CONTROL, val); POSTING_READ(PCH_DREF_CONTROL); udelay(200); } else { DRM_DEBUG_KMS("Disabling SSC entirely\n"); - temp &= ~DREF_CPU_SOURCE_OUTPUT_MASK; + val &= ~DREF_CPU_SOURCE_OUTPUT_MASK; /* Turn off CPU output */ - temp |= DREF_CPU_SOURCE_OUTPUT_DISABLE; + val |= DREF_CPU_SOURCE_OUTPUT_DISABLE; - I915_WRITE(PCH_DREF_CONTROL, temp); + I915_WRITE(PCH_DREF_CONTROL, val); POSTING_READ(PCH_DREF_CONTROL); udelay(200); /* Turn off the SSC source */ - temp &= ~DREF_SSC_SOURCE_MASK; - temp |= DREF_SSC_SOURCE_DISABLE; + val &= ~DREF_SSC_SOURCE_MASK; + val |= DREF_SSC_SOURCE_DISABLE; /* Turn off SSC1 */ - temp &= ~ DREF_SSC1_ENABLE; + val &= ~DREF_SSC1_ENABLE; - I915_WRITE(PCH_DREF_CONTROL, temp); + I915_WRITE(PCH_DREF_CONTROL, val); POSTING_READ(PCH_DREF_CONTROL); udelay(200); } + + BUG_ON(val != final); } /* Sequence to enable CLKOUT_DP for FDI usage and configure PCH FDI I/O. */ |