[Intel-gfx] [PATCH] drm/i915: reset GPU after clearing CSunit clock gating on gen6

[Jesse Barnes]

Needed to make sure we can enter/exit RC6 properly.

v2: move to modeset_init since reset in init_clock_gating is too early

Cc: James Kukunas <james.t.kukunas at intel.com>
Cc: Arjan van de Ven <arjan at linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
---
 drivers/gpu/drm/i915/i915_dma.c |    7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 80ed751..9330c56 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1321,6 +1321,13 @@ static int i915_load_modeset_init(struct drm_device *dev)
 	/* We're off and running w/KMS */
 	dev_priv->mm.suspended = 0;
 
+	/*
+	 * SNB needs to reset after disabling CSunit clock gating or RC6 may
+	 * break.
+	 */
+	if (IS_GEN6(dev))
+		i915_reset(dev);
+
 	return 0;
 
 cleanup_irq:
-- 
1.7.9.5