[PATCH 3.16.y-ckt 022/180] drm/i915/chv: Remove Wait for a previous gfx force-off

[Luis Henriques]

3.16.7-ckt11 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Deepak S <deepak.s at linux.intel.com>

commit c9c52e24194a741f9fca96e7aa965f0fa36af504 upstream.

On CHV, PUNIT team confirmed that 'VLV_GFX_CLK_STATUS_BIT' is not a
sticky bit and it will always be set. So ignore Check for previous
Gfx force off during suspend and allow the force clk as part S0ix
Sequence

Signed-off-by: Deepak S <deepak.s at linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula at intel.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/gpu/drm/i915/i915_drv.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index a458e8393378..7a0fc58d372e 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1176,11 +1176,13 @@ int vlv_force_gfx_clock(struct drm_i915_private *dev_priv, bool force_on)
 	int err;
 
 	val = I915_READ(VLV_GTLC_SURVIVABILITY_REG);
-	WARN_ON(!!(val & VLV_GFX_CLK_FORCE_ON_BIT) == force_on);
 
 #define COND (I915_READ(VLV_GTLC_SURVIVABILITY_REG) & VLV_GFX_CLK_STATUS_BIT)
 	/* Wait for a previous force-off to settle */
-	if (force_on) {
+	if (force_on && !IS_CHERRYVIEW(dev_priv->dev)) {
+		/* WARN_ON only for the Valleyview */
+		WARN_ON(!!(val & VLV_GFX_CLK_FORCE_ON_BIT) == force_on);
+
 		err = wait_for(!COND, 20);
 		if (err) {
 			DRM_ERROR("timeout waiting for GFX clock force-off (%08x)\n",