drm/i915: Cantiga+ cannot handle a hsync front porch of 0
This addresses WaPruneModeWithIncorrectHsyncOffset.
Bugzilla: http://bugs.freedesktop.org/show_bug.cgi?id=50236
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 42c5758..778cbb8 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3602,6 +3602,13 @@
if (!(adjusted_mode->private_flags & INTEL_MODE_CRTC_TIMINGS_SET))
drm_mode_set_crtcinfo(adjusted_mode, 0);
+ /* WaPruneModeWithIncorrectHsyncOffset: Cantiga+ cannot handle modes
+ * with a hsync front porch of 0.
+ */
+ if ((INTEL_INFO(dev)->gen > 4 || IS_G4X(dev)) &&
+ adjusted_mode->hsync_start == adjusted_mode->hdisplay)
+ return false;
+
return true;
}