From 1d1d0e277ee706413e2a3b3c671e3cf29c8d0dd2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@linux.intel.com>
Date: Wed, 4 Sep 2013 18:30:05 +0300
Subject: [PATCH] drm/i915: pipe_src_w must be even in LVDS dual channel, DVO
 ganged, and double wide mode
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Pipe horizontal source size must be even when either LVDS dual channel
mode, DVO ganged mode, or pipe double wide mode is used.

We must round it down since we can never increase the user specified
viewport size.

The actual error from an odd pipe source width looks like a diagonal
shift, like you might get from a bad stride.

v2: s/ganaged/ganged/

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 drivers/gpu/drm/i915/intel_display.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 91631bf354e6..9bbb6ea34d06 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4166,6 +4166,16 @@ static int intel_crtc_compute_config(struct intel_crtc *crtc,
 			return -EINVAL;
 	}
 
+	/*
+	 * Pipe horizontal size must be even in:
+	 * - DVO ganged mode
+	 * - LVDS dual channel mode
+	 * - Double wide pipe
+	 */
+	if ((intel_pipe_has_type(&crtc->base, INTEL_OUTPUT_LVDS) &&
+	     intel_is_dual_link_lvds(dev)) || pipe_config->double_wide)
+		pipe_config->pipe_src_w &= ~1;
+
 	/* Cantiga+ cannot handle modes with a hsync front porch of 0.
 	 * WaPruneModeWithIncorrectHsyncOffset:ctg,elk,ilk,snb,ivb,vlv,hsw.
 	 */
-- 
GitLab