[Intel-gfx] [PATCH 2/4] drm/i915: Restore the display config after a GPU reset on gen4

[ville.syrjala at linux.intel.com]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

On pre-ctg GPU reset also resets the display hardware. Force a mode
restore after the GPU reset, and also re-init clock gating.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_drv.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index b948c71..2ec3796 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -794,6 +794,14 @@ int i915_reset(struct drm_device *dev)
 		if (INTEL_INFO(dev)->gen > 5)
 			intel_reset_gt_powersave(dev);
 
+		if (IS_GEN4(dev) && !IS_G4X(dev)) {
+			intel_init_clock_gating(dev);
+
+			drm_modeset_lock_all(dev);
+			intel_modeset_setup_hw_state(dev, true);
+			drm_modeset_unlock_all(dev);
+		}
+
 		intel_hpd_init(dev);
 	} else {
 		mutex_unlock(&dev->struct_mutex);
-- 
1.8.5.5