From: Jesse Barnes <jbarnes@virtuousgeek.org>
Date: Fri, 24 Jun 2011 19:19:21 +0000 (-0700)
Subject: drm/i915: set bpc for DP transcoder
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=9325c9f088c42e3e07475d4f733ee6539ebf9c0b;p=linux-beck.git

drm/i915: set bpc for DP transcoder

This may not be the default value, so pull the bpc out of the pipe reg
and write it to the DP transcoder so proper dithering and signaling
occurs.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
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 c675f9f27d9c..ce3666d53f57 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2622,6 +2622,7 @@ static void ironlake_pch_enable(struct drm_crtc *crtc)
 	/* For PCH DP, enable TRANS_DP_CTL */
 	if (HAS_PCH_CPT(dev) &&
 	    intel_pipe_has_type(crtc, INTEL_OUTPUT_DISPLAYPORT)) {
+		u32 bpc = (I915_READ(PIPECONF(pipe)) & PIPE_BPC_MASK) >> 5;
 		reg = TRANS_DP_CTL(pipe);
 		temp = I915_READ(reg);
 		temp &= ~(TRANS_DP_PORT_SEL_MASK |
@@ -2629,7 +2630,7 @@ static void ironlake_pch_enable(struct drm_crtc *crtc)
 			  TRANS_DP_BPC_MASK);
 		temp |= (TRANS_DP_OUTPUT_ENABLE |
 			 TRANS_DP_ENH_FRAMING);
-		temp |= TRANS_DP_8BPC;
+		temp |= bpc << 9; /* same format but at 11:9 */
 
 		if (crtc->mode.flags & DRM_MODE_FLAG_PHSYNC)
 			temp |= TRANS_DP_HSYNC_ACTIVE_HIGH;