[Intel-gfx] [PATCH 2/7] drm/i915: use 125MHz reference clock for PCH attached eDP

[Jesse Barnes]

Fix the test so we don't try to use the 450MHz refclk on PCH attached
eDP.

References:
  https://bugs.freedesktop.org/show_bug.cgi?id=29141

Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
---
 drivers/gpu/drm/i915/intel_dp.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 625b480..47eac03 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -246,8 +246,11 @@ intel_dp_aux_ch(struct intel_dp *intel_dp,
 	/* The clock divider is based off the hrawclk,
 	 * and would like to run at 2MHz. So, take the
 	 * hrawclk value and divide by 2 and use that
+	 *
+	 * Note that PCH attached eDP panels should use a 125MHz input
+	 * clock divider.
 	 */
-	if (IS_eDP(intel_dp)) {
+	if (IS_eDP(intel_dp) && !IS_PCH_eDP(intel_dp)) {
 		if (IS_GEN6(dev))
 			aux_clock_divider = 200; /* SNB eDP input clock at 400Mhz */
 		else
-- 
1.6.3.3