drm/i915: Fix DDC on some systems by clearing BIOS GMBUS setup.

This is a sync of a fix I made in the old UMS code.  If the BIOS uses
the GMBUS and doesn't clear that setup, then our bit-banging I2C can
fail, leading to monitors not being detected.

Signed-off-by: Eric Anholt <eric@anholt.net>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/i915_suspend.c b/drivers/gpu/drm/i915/i915_suspend.c
index cd10d9b8181f..c5a6df93e1b6 100644
--- a/drivers/gpu/drm/i915/i915_suspend.c
+++ b/drivers/gpu/drm/i915/i915_suspend.c
@@ -27,7 +27,7 @@
 #include "drmP.h"
 #include "drm.h"
 #include "i915_drm.h"
-#include "i915_drv.h"
+#include "intel_drv.h"
 
 static bool i915_pipe_enabled(struct drm_device *dev, enum pipe pipe)
 {
@@ -816,6 +816,9 @@ int i915_restore_state(struct drm_device *dev)
         for (i = 0; i < 3; i++)
                 I915_WRITE(SWF30 + (i << 2), dev_priv->saveSWF2[i]);
 
+        /* I2C state */
+        intel_i2c_reset_gmbus(dev);
+
         return 0;
 }