[PATCH 3/3] drm/i915: push struct_mutex locking down to ironlake_enable_rc6

[Daniel Vetter <daniel.vetter@ffwll.ch>]

Originally dev->struct_mutex protected all kinds of things for rps/ips
(debugfs access, driver state, ...). Nowadays we have
dev_priv->rps.lock for this, so only the ilk ips code needs it really.

Push the locking down. I haven't yet changed the cleanup side since
there we lock large parts of the code with struct_mutex.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 drivers/gpu/drm/i915/intel_display.c |    2 --
 drivers/gpu/drm/i915/intel_pm.c      |   13 +++++++++----
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index da1ad9c..91e99a6 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -8945,9 +8945,7 @@ void intel_modeset_init_hw(struct drm_device *dev)
 
 	intel_init_clock_gating(dev);
 
-	mutex_lock(&dev->struct_mutex);
 	intel_enable_gt_powersave(dev);
-	mutex_unlock(&dev->struct_mutex);
 }
 
 void intel_modeset_init(struct drm_device *dev)
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 7658c39..3ed7114 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -2715,6 +2715,8 @@ void ironlake_teardown_rc6(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
+	WARN_ON(!mutex_is_locked(&dev->struct_mutex));
+
 	if (dev_priv->ips.renderctx) {
 		i915_gem_object_unpin(dev_priv->ips.renderctx);
 		drm_gem_object_unreference(&dev_priv->ips.renderctx->base);
@@ -2778,11 +2780,11 @@ static void ironlake_enable_rc6(struct drm_device *dev)
 	if (!intel_enable_rc6(dev))
 		return;
 
-	WARN_ON(!mutex_is_locked(&dev->struct_mutex));
+	mutex_lock(&dev->struct_mutex);
 
 	ret = ironlake_setup_rc6(dev);
 	if (ret)
-		return;
+		goto unlock;
 
 	was_interruptible = dev_priv->mm.interruptible;
 	dev_priv->mm.interruptible = false;
@@ -2795,7 +2797,7 @@ static void ironlake_enable_rc6(struct drm_device *dev)
 	if (ret) {
 		ironlake_teardown_rc6(dev);
 		dev_priv->mm.interruptible = was_interruptible;
-		return;
+		goto unlock;
 	}
 
 	intel_ring_emit(ring, MI_SUSPEND_FLUSH | MI_SUSPEND_FLUSH_EN);
@@ -2820,11 +2822,14 @@ static void ironlake_enable_rc6(struct drm_device *dev)
 	if (ret) {
 		DRM_ERROR("failed to enable ironlake power power savings\n");
 		ironlake_teardown_rc6(dev);
-		return;
+		goto unlock;
 	}
 
 	I915_WRITE(PWRCTXA, dev_priv->ips.pwrctx->gtt_offset | PWRCTX_EN);
 	I915_WRITE(RSTDBYCTL, I915_READ(RSTDBYCTL) & ~RCX_SW_EXIT);
+
+unlock:
+	mutex_lock(&dev->struct_mutex);
 }
 
 static unsigned long intel_pxfreq(u32 vidfreq)
-- 
1.7.10.4