drm/i915: Beef up skl_sanitize_cdclk() a bit
Also verify the DPLL_CTRL1 register value in skl_sanitize_cdclk(), throw
out a few unneeded variables, and write the CDCLK_CTL check a bit more
legible way.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463172100-24715-10-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Imre Deak <imre.deak@intel.com>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 2d8630f..b2adb01 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -5709,9 +5709,7 @@
int skl_sanitize_cdclk(struct drm_i915_private *dev_priv)
{
- uint32_t lcpll1 = I915_READ(LCPLL1_CTL);
- uint32_t cdctl = I915_READ(CDCLK_CTL);
- int freq = dev_priv->cdclk_freq;
+ uint32_t cdctl, expected;
/*
* check if the pre-os intialized the display
@@ -5722,7 +5720,14 @@
goto sanitize;
/* Is PLL enabled and locked ? */
- if (!((lcpll1 & LCPLL_PLL_ENABLE) && (lcpll1 & LCPLL_PLL_LOCK)))
+ if ((I915_READ(LCPLL1_CTL) & (LCPLL_PLL_ENABLE | LCPLL_PLL_LOCK)) !=
+ (LCPLL_PLL_ENABLE | LCPLL_PLL_LOCK))
+ goto sanitize;
+
+ if ((I915_READ(DPLL_CTRL1) & (DPLL_CTRL1_HDMI_MODE(SKL_DPLL0) |
+ DPLL_CTRL1_SSC(SKL_DPLL0) |
+ DPLL_CTRL1_OVERRIDE(SKL_DPLL0))) !=
+ DPLL_CTRL1_OVERRIDE(SKL_DPLL0))
goto sanitize;
/* DPLL okay; verify the cdclock
@@ -5731,7 +5736,10 @@
* decimal part is programmed wrong from BIOS where pre-os does not
* enable display. Verify the same as well.
*/
- if (cdctl == ((cdctl & CDCLK_FREQ_SEL_MASK) | skl_cdclk_decimal(freq)))
+ cdctl = I915_READ(CDCLK_CTL);
+ expected = (cdctl & CDCLK_FREQ_SEL_MASK) |
+ skl_cdclk_decimal(dev_priv->cdclk_freq);
+ if (cdctl == expected)
/* All well; nothing to sanitize */
return false;
sanitize: