[Intel-gfx] [PATCH 2/2] drm/i915: Enable the PCH PLL for all generations after link training

[Chris Wilson]

Hidden away within one chipset specific path was the necessary logic to
turn on the PLL. This needs to be done everywhere in order for us to
drive any display! As such as soon as we tested on a non-CougarPoint
chipset, we failed to bring up any DisplayPorts and generated a nice set
of assertion failures in the process. At least one part of our logic is
working, the part that assumes that we have no idea what we are doing.

Reported-by: guang.a.yang at intel.com
References: https://bugs.freedesktop.org/show_bug.cgi?id=49712
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Jesse Barnes <jbarnes at virtuousgeek.org>
---
 drivers/gpu/drm/i915/intel_display.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index a679a9a..d0112ec 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2887,14 +2887,14 @@ static void ironlake_pch_enable(struct drm_crtc *crtc)
 	/* For PCH output, training FDI link */
 	dev_priv->display.fdi_link_train(crtc);
 
+	intel_enable_pch_pll(intel_crtc);
+
 	if (HAS_PCH_LPT(dev)) {
 		DRM_DEBUG_KMS("LPT detected: programming iCLKIP\n");
 		lpt_program_iclkip(crtc);
 	} else if (HAS_PCH_CPT(dev)) {
 		u32 sel;
 
-		intel_enable_pch_pll(intel_crtc);
-
 		temp = I915_READ(PCH_DPLL_SEL);
 		switch (pipe) {
 		default:
-- 
1.7.10