drm/i915: save/resume forcewake lock fixes

The lock must be held for the saving and restoring of VGA state.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
CC: Alexander Zhaunerchyk <alex.vizor@gmail.com>
CC: Andrey Rahmatullin <wrar@wrar.name>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_suspend.c b/drivers/gpu/drm/i915/i915_suspend.c
index 60a94d2b5264..e8152d23d5b6 100644
--- a/drivers/gpu/drm/i915/i915_suspend.c
+++ b/drivers/gpu/drm/i915/i915_suspend.c
@@ -678,6 +678,7 @@ void i915_save_display(struct drm_device *dev)
         }
 
         /* VGA state */
+        mutex_lock(&dev->struct_mutex);
         dev_priv->saveVGA0 = I915_READ(VGA0);
         dev_priv->saveVGA1 = I915_READ(VGA1);
         dev_priv->saveVGA_PD = I915_READ(VGA_PD);
@@ -687,6 +688,7 @@ void i915_save_display(struct drm_device *dev)
                 dev_priv->saveVGACNTRL = I915_READ(VGACNTRL);
 
         i915_save_vga(dev);
+        mutex_unlock(&dev->struct_mutex);
 }
 
 void i915_restore_display(struct drm_device *dev)
@@ -780,6 +782,8 @@ void i915_restore_display(struct drm_device *dev)
                 I915_WRITE(CPU_VGACNTRL, dev_priv->saveVGACNTRL);
         else
                 I915_WRITE(VGACNTRL, dev_priv->saveVGACNTRL);
+
+        mutex_lock(&dev->struct_mutex);
         I915_WRITE(VGA0, dev_priv->saveVGA0);
         I915_WRITE(VGA1, dev_priv->saveVGA1);
         I915_WRITE(VGA_PD, dev_priv->saveVGA_PD);
@@ -787,6 +791,7 @@ void i915_restore_display(struct drm_device *dev)
         udelay(150);
 
         i915_restore_vga(dev);
+        mutex_unlock(&dev->struct_mutex);
 }
 
 int i915_save_state(struct drm_device *dev)