drm/i915: Reject odd pipe source width with double wide/dual link

In order to guarantee that pipe_src_w/h matches the user mode h/vdisplay
we must not adjust pipe_src_w to accommodate double wide/dual link.
Instead just reject the mode outright.

This will allows us to rely on crtc_state->mode for plane clipping.

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171123190502.28449-2-ville.syrjala@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Thierry Reding <treding@nvidia.com>

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 0cd355978ab42a880ea3a11600e66536925edd0e..dc84a3bd7777fe04ef1cb97ee70e78bde8fe7c92 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -6372,9 +6372,18 @@ static int intel_crtc_compute_config(struct intel_crtc *crtc,
         * - LVDS dual channel mode
         * - Double wide pipe
         */
-       if ((intel_crtc_has_type(pipe_config, INTEL_OUTPUT_LVDS) &&
-            intel_is_dual_link_lvds(dev)) || pipe_config->double_wide)
-               pipe_config->pipe_src_w &= ~1;
+       if (pipe_config->pipe_src_w & 1) {
+               if (pipe_config->double_wide) {
+                       DRM_DEBUG_KMS("Odd pipe source width not supported with double wide pipe\n");
+                       return -EINVAL;
+               }
+
+               if (intel_crtc_has_type(pipe_config, INTEL_OUTPUT_LVDS) &&
+                   intel_is_dual_link_lvds(dev)) {
+                       DRM_DEBUG_KMS("Odd pipe source width not supported with dual link LVDS\n");
+                       return -EINVAL;
+               }
+       }
 
        /* Cantiga+ cannot handle modes with a hsync front porch of 0.
         * WaPruneModeWithIncorrectHsyncOffset:ctg,elk,ilk,snb,ivb,vlv,hsw.