drm/i915: don't disable a PCH DPLL that's in use
If a PCH pipe PLL is being used by transcoder C, don't disable it.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Keith Packard <keithp@keithp.com>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 2e00c8a..bdab82b 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1204,7 +1204,8 @@
enum pipe pipe)
{
int reg;
- u32 val;
+ u32 val, pll_mask = TRANSC_DPLL_ENABLE | TRANSC_DPLLB_SEL,
+ pll_sel = TRANSC_DPLL_ENABLE;
if (pipe > 1)
return;
@@ -1215,6 +1216,15 @@
/* Make sure transcoder isn't still depending on us */
assert_transcoder_disabled(dev_priv, pipe);
+ if (pipe == 0)
+ pll_sel |= TRANSC_DPLLA_SEL;
+ else if (pipe == 1)
+ pll_sel |= TRANSC_DPLLB_SEL;
+
+
+ if ((I915_READ(PCH_DPLL_SEL) & pll_mask) == pll_sel)
+ return;
+
reg = PCH_DPLL(pipe);
val = I915_READ(reg);
val &= ~DPLL_VCO_ENABLE;