On Thu, 2014-05-29 at 14:11 -0700, Jesse Barnes wrote:
> From: Kristen Carlson Accardi <kristen@linux.intel.com>
> 
> This matches the runtime suspend paths and allows the system to enter
> the lowest power mode at freeze time.
> 
> Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
> ---
>  drivers/gpu/drm/i915/i915_drv.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index b6211d7..24dc856 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -558,6 +558,9 @@ static int i915_drm_freeze(struct drm_device *dev)
>  
>  	intel_display_set_init_power(dev_priv, false);
>  
> +	if (IS_HASWELL(dev) || IS_BROADWELL(dev))
> +		hsw_enable_pc8(dev_priv);
> +
>  	return 0;
>  }
>  
> @@ -618,6 +621,9 @@ static int __i915_drm_thaw(struct drm_device *dev, bool restore_gtt_mappings)
>  {
>  	struct drm_i915_private *dev_priv = dev->dev_private;
>  
> +	if (IS_HASWELL(dev) || IS_BROADWELL(dev))
> +		hsw_disable_pc8(dev_priv);

I would put this before we access any of the HW regs in thaw_early() and
correspondingly the above call to hsw_enable_pc8() to suspend_late()
before we call pci_disable_device().

With that change this is:
Reviewed-by: Imre Deak <imre.deak@intel.com>

> +
>  	if (drm_core_check_feature(dev, DRIVER_MODESET) &&
>  	    restore_gtt_mappings) {
>  		mutex_lock(&dev->struct_mutex);