[3.16.y-ckt stable] Patch "drm/i915/chv: Remove Wait for a previous gfx force-off" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    drm/i915/chv: Remove Wait for a previous gfx force-off

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt11.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

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>From 51d73171df477dc488e4db6388f56ccad5ad3702 Mon Sep 17 00:00:00 2001
From: Deepak S <deepak.s at linux.intel.com>
Date: Sat, 28 Mar 2015 15:23:34 +0530
Subject: drm/i915/chv: Remove Wait for a previous gfx force-off
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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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",