drm/i915: quirk away broken OpRegion VBT

BugLink: http://bugs.launchpad.net/bugs/981162

commit 25e341cfc33d94435472983825163e97fe370a6c upstream.

Somehow the BIOS manages to screw things up when copying the VBT
around, because the one we scrap from the VBIOS rom actually works.

Tested-by: Markus Heinz <markus.heinz@uni-dortmund.de>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=28812
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Leann Ogasawara <leann.ogasawara@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index 63880e2..22efb08 100644 (file)
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -24,6 +24,7 @@
  *    Eric Anholt <eric@anholt.net>
  *
  */
+#include <linux/dmi.h>
 #include <drm/drm_dp_helper.h>
 #include "drmP.h"
 #include "drm.h"
@@ -621,6 +622,26 @@ init_vbt_defaults(struct drm_i915_private *dev_priv)
        dev_priv->edp.bpp = 18;
 }
 
+static int __init intel_no_opregion_vbt_callback(const struct dmi_system_id *id)
+{
+       DRM_DEBUG_KMS("Falling back to manually reading VBT from "
+                     "VBIOS ROM for %s\n",
+                     id->ident);
+       return 1;
+}
+
+static const struct dmi_system_id intel_no_opregion_vbt[] = {
+       {
+               .callback = intel_no_opregion_vbt_callback,
+               .ident = "ThinkCentre A57",
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "97027RG"),
+               },
+       },
+       { }
+};
+
 /**
  * intel_parse_bios - find VBT and initialize settings from the BIOS
  * @dev: DRM device
@@ -641,7 +662,7 @@ intel_parse_bios(struct drm_device *dev)
        init_vbt_defaults(dev_priv);
 
        /* XXX Should this validation be moved to intel_opregion.c? */
-       if (dev_priv->opregion.vbt) {
+       if (!dmi_check_system(intel_no_opregion_vbt) && dev_priv->opregion.vbt) {
                struct vbt_header *vbt = dev_priv->opregion.vbt;
                if (memcmp(vbt->signature, "$VBT", 4) == 0) {
                        DRM_DEBUG_KMS("Using VBT from OpRegion: %20s\n",