drm/i915/bxt: Suspend power domains during suspend-to-idle

On SKL/KBL suspend-to-idle (aka freeze/s0ix) is performed with DMC
firmware assistance where the target display power state is DC6. On
Broxton on the other hand we don't use the firmware for this, but rely
instead on a manual DC9 flow. For this we have to uninitialize the
display following the BSpec display uninit sequence, just as during
S3/S4, so make sure we follow this sequence.

CC: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1459515767-29228-8-git-send-email-imre.deak@intel.com

drivers/gpu/drm/i915/i915_drv.c

@@ -657,7 +657,8 @@ static int i915_drm_suspend_late(struct drm_device *drm_dev, bool hibernation)
 
 	disable_rpm_wakeref_asserts(dev_priv);
 
-	fw_csr = suspend_to_idle(dev_priv) && dev_priv->csr.dmc_payload;
+	fw_csr = !IS_BROXTON(dev_priv) &&
+		suspend_to_idle(dev_priv) && dev_priv->csr.dmc_payload;
 	/*
 	 * In case of firmware assisted context save/restore don't manually
 	 * deinit the power domains. This also means the CSR/DMC firmware will
@@ -837,7 +838,8 @@ static int i915_drm_resume_early(struct drm_device *dev)
 
 	intel_uncore_sanitize(dev);
 
-	if (!(dev_priv->suspended_to_idle && dev_priv->csr.dmc_payload))
+	if (IS_BROXTON(dev_priv) ||
+	    !(dev_priv->suspended_to_idle && dev_priv->csr.dmc_payload))
 		intel_power_domains_init_hw(dev_priv, true);
 
 out: