drm/i915: handle bogus VBT panel timing

We've seen cases in the wild where the VBT sync data is wrong, so add
some code to fix it up in that case, taking care to make sure that the
total is greater than the sync end.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Dave Airlie <airlied@linux.ie>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index 65be30dccc77..fc28e2bbd542 100644
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -111,6 +111,12 @@ parse_panel_data(struct drm_i915_private *dev_priv, struct bdb_header *bdb)
         panel_fixed_mode->clock = dvo_timing->clock * 10;
         panel_fixed_mode->type = DRM_MODE_TYPE_PREFERRED;
 
+        /* Some VBTs have bogus h/vtotal values */
+        if (panel_fixed_mode->hsync_end > panel_fixed_mode->htotal)
+                panel_fixed_mode->htotal = panel_fixed_mode->hsync_end + 1;
+        if (panel_fixed_mode->vsync_end > panel_fixed_mode->vtotal)
+                panel_fixed_mode->vtotal = panel_fixed_mode->vsync_end + 1;
+
         drm_mode_set_name(panel_fixed_mode);
 
         dev_priv->vbt_mode = panel_fixed_mode;