[3.16.y-ckt stable] Patch "drm/i915/vlv: remove wait for previous GFX clk disable request" 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/vlv: remove wait for previous GFX clk disable request

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

------

>From ea88728a1db6788bd5cf6968876192ebc2c5d7a5 Mon Sep 17 00:00:00 2001
From: Jesse Barnes <jbarnes at virtuousgeek.org>
Date: Wed, 1 Apr 2015 14:22:58 -0700
Subject: drm/i915/vlv: remove wait for previous GFX clk disable request

commit 5df0582bf036bb5f9a8ad8db5884fe13a55347d1 upstream.

Looks like it was introduced in:

commit 650ad970a39f8b6164fe8613edc150f585315289
Author: Imre Deak <imre.deak at intel.com>
Date:   Fri Apr 18 16:35:02 2014 +0300

    drm/i915: vlv: factor out vlv_force_gfx_clock and check for pending force-of

but I'm not sure why.  It has caused problems for us in the past (see
85250ddff7a6 "drm/i915/chv: Remove Wait for a previous gfx force-off"
and 8d4eee9cd7a1 "drm/i915: vlv: increase timeout when forcing on the
GFX clock") and doesn't seem to be required, so let's just drop it.

References: https://bugs.freedesktop.org/show_bug.cgi?id=89611
Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
Tested-by: Darren Hart <dvhart at linux.intel.com>
Reviewed-by: Deepak S <deepak.s at linux.intel.com>
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 | 14 --------------
 1 file changed, 14 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 7a0fc58d372e..caef2e1774b3 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1175,21 +1175,7 @@ int vlv_force_gfx_clock(struct drm_i915_private *dev_priv, bool force_on)
 	u32 val;
 	int err;

-	val = I915_READ(VLV_GTLC_SURVIVABILITY_REG);
-
 #define COND (I915_READ(VLV_GTLC_SURVIVABILITY_REG) & VLV_GFX_CLK_STATUS_BIT)
-	/* Wait for a previous force-off to settle */
-	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",
-				  I915_READ(VLV_GTLC_SURVIVABILITY_REG));
-			return err;
-		}
-	}

 	val = I915_READ(VLV_GTLC_SURVIVABILITY_REG);
 	val &= ~VLV_GFX_CLK_FORCE_ON_BIT;