This reverts commit f165d2834ceb3d5c29bebadadc27629bebf402ac. It breaks one of our CI systems. Quoting from Ville: [ 13.100979] [drm:ironlake_init_pch_refclk] has_panel 1 has_lvds 1 has_ck505 0 using_ssc_source 1 [ 13.101413] ------------[ cut here ]------------ [ 13.101429] kernel BUG at drivers/gpu/drm/i915/intel_display.c:8528! "which is the 'BUG_ON(val != final)' at the end of ironlake_init_pch_refclk()." Cc: stable@xxxxxxxxxxxxxxx Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Cc: Lyude <cpaul@xxxxxxxxxx> Cc: marius.c.vlad@xxxxxxxxx References: https://www.spinics.net/lists/dri-devel/msg109557.html Acked-by: Lyude <cpaul@xxxxxxxxxx> Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx> --- drivers/gpu/drm/i915/intel_display.c | 49 ++++++++++-------------------------- 1 file changed, 13 insertions(+), 36 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 12ff79594bc1..473c8fdb38b9 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -8361,14 +8361,12 @@ static void ironlake_init_pch_refclk(struct drm_device *dev) { struct drm_i915_private *dev_priv = dev->dev_private; struct intel_encoder *encoder; - int i; u32 val, final; bool has_lvds = false; bool has_cpu_edp = false; bool has_panel = false; bool has_ck505 = false; bool can_ssc = false; - bool using_ssc_source = false; /* We need to take the global config into account */ for_each_intel_encoder(dev, encoder) { @@ -8395,22 +8393,8 @@ static void ironlake_init_pch_refclk(struct drm_device *dev) can_ssc = true; } - /* Check if any DPLLs are using the SSC source */ - for (i = 0; i < dev_priv->num_shared_dpll; i++) { - u32 temp = I915_READ(PCH_DPLL(i)); - - if (!(temp & DPLL_VCO_ENABLE)) - continue; - - if ((temp & PLL_REF_INPUT_MASK) == - PLLB_REF_INPUT_SPREADSPECTRUMIN) { - using_ssc_source = true; - break; - } - } - - DRM_DEBUG_KMS("has_panel %d has_lvds %d has_ck505 %d using_ssc_source %d\n", - has_panel, has_lvds, has_ck505, using_ssc_source); + DRM_DEBUG_KMS("has_panel %d has_lvds %d has_ck505 %d\n", + has_panel, has_lvds, has_ck505); /* Ironlake: try to setup display ref clock before DPLL * enabling. This is only under driver's control after @@ -8430,12 +8414,9 @@ static void ironlake_init_pch_refclk(struct drm_device *dev) else final |= DREF_NONSPREAD_SOURCE_ENABLE; + final &= ~DREF_SSC_SOURCE_MASK; final &= ~DREF_CPU_SOURCE_OUTPUT_MASK; - - if (!using_ssc_source) { - final &= ~DREF_SSC_SOURCE_MASK; - final &= ~DREF_SSC1_ENABLE; - } + final &= ~DREF_SSC1_ENABLE; if (has_panel) { final |= DREF_SSC_SOURCE_ENABLE; @@ -8498,7 +8479,7 @@ static void ironlake_init_pch_refclk(struct drm_device *dev) POSTING_READ(PCH_DREF_CONTROL); udelay(200); } else { - DRM_DEBUG_KMS("Disabling CPU source output\n"); + DRM_DEBUG_KMS("Disabling SSC entirely\n"); val &= ~DREF_CPU_SOURCE_OUTPUT_MASK; @@ -8509,20 +8490,16 @@ static void ironlake_init_pch_refclk(struct drm_device *dev) POSTING_READ(PCH_DREF_CONTROL); udelay(200); - if (!using_ssc_source) { - DRM_DEBUG_KMS("Disabling SSC source\n"); - - /* Turn off the SSC source */ - val &= ~DREF_SSC_SOURCE_MASK; - val |= DREF_SSC_SOURCE_DISABLE; + /* Turn off the SSC source */ + val &= ~DREF_SSC_SOURCE_MASK; + val |= DREF_SSC_SOURCE_DISABLE; - /* Turn off SSC1 */ - val &= ~DREF_SSC1_ENABLE; + /* Turn off SSC1 */ + val &= ~DREF_SSC1_ENABLE; - I915_WRITE(PCH_DREF_CONTROL, val); - POSTING_READ(PCH_DREF_CONTROL); - udelay(200); - } + I915_WRITE(PCH_DREF_CONTROL, val); + POSTING_READ(PCH_DREF_CONTROL); + udelay(200); } BUG_ON(val != final); -- 2.8.1 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html