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Commit 8c07eb68 authored by Daniel Vetter's avatar Daniel Vetter
Browse files

Revert "drm/i915/ilk: Don't disable SSC source if it's in use" 

This reverts commit f165d283.

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@vger.kernel.org
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Lyude <cpaul@redhat.com>
Cc: marius.c.vlad@intel.com
References: https://www.spinics.net/lists/dri-devel/msg109557.html


Acked-by: default avatarLyude <cpaul@redhat.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@intel.com>
parent d1b4eefd

drivers/gpu/drm/i915/intel_display.c

+13 −36
Original line number Diff line number Diff line
@@ -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_CPU_SOURCE_OUTPUT_MASK;



	if (!using_ssc_source) {

	final &= ~DREF_SSC_SOURCE_MASK;

	final &= ~DREF_CPU_SOURCE_OUTPUT_MASK;

	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;
@@ -8509,9 +8490,6 @@ 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;
@@ -8523,7 +8501,6 @@ static void ironlake_init_pch_refclk(struct drm_device *dev) 
		POSTING_READ(PCH_DREF_CONTROL);

		udelay(200);

	}

	}



	BUG_ON(val != final);

}