drm/i915: Add a dual link lvds quirk for MacBook Pro 8,2

When booting with EFI, Apple botched this one up.

v2: Switch the quirk dmesg output to DRM_INFO.
v3: Actually git add the new things ...

Tested-by: Austin Lund <austin.lund@gmail.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=42842
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 22 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 2bd08ef056d9..6ec81b43ffc0 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -24,6 +24,7 @@
  *      Eric Anholt <eric@anholt.net>
  */
 
+#include <linux/dmi.h>
 #include <linux/cpufreq.h>
 #include <linux/module.h>
 #include <linux/input.h>
@@ -418,6 +419,24 @@ static void vlv_init_dpio(struct drm_device *dev)
         POSTING_READ(DPIO_CTL);
 }
 
+static int intel_dual_link_lvds_callback(const struct dmi_system_id *id)
+{
+        DRM_INFO("Forcing lvds to dual link mode on %s\n", id->ident);
+        return 1;
+}
+
+static const struct dmi_system_id intel_dual_link_lvds[] = {
+        {
+                .callback = intel_dual_link_lvds_callback,
+                .ident = "Apple MacBook Pro (Core i5/i7 Series)",
+                .matches = {
+                        DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
+                        DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro8,2"),
+                },
+        },
+        { }     /* terminating entry */
+};
+
 static bool is_dual_link_lvds(struct drm_i915_private *dev_priv,
                               unsigned int reg)
 {
@@ -427,6 +446,9 @@ static bool is_dual_link_lvds(struct drm_i915_private *dev_priv,
         if (i915_lvds_channel_mode > 0)
                 return i915_lvds_channel_mode == 2;
 
+        if (dmi_check_system(intel_dual_link_lvds))
+                return true;
+
         if (dev_priv->lvds_val)
                 val = dev_priv->lvds_val;
         else {