Patch "drm/i915/gen9: Fix PCODE polling during SAGV disabling" has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    drm/i915/gen9: Fix PCODE polling during SAGV disabling

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-i915-gen9-fix-pcode-polling-during-sagv-disabling.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From dccf82ad1775f2b9c36ec85e25e39d88c7e86818 Mon Sep 17 00:00:00 2001
From: Imre Deak <imre.deak@intel.com>
Date: Mon, 5 Dec 2016 18:27:38 +0200
Subject: drm/i915/gen9: Fix PCODE polling during SAGV disabling
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

From: Imre Deak <imre.deak@intel.com>

commit dccf82ad1775f2b9c36ec85e25e39d88c7e86818 upstream.

According to the previous patch, it's possible atm that we call
intel_do_sagv_disable() only once during the 1ms period and time out if
that call fails. As opposed to this the spec says that we need to keep
retrying this request for a 1ms duration, so let's do this similarly to
the CDCLK change notification request.

v4-5:
- Rebased on the reply_mask, reply change.
v6:
- Remove w/s change. (Lyude)
- Rebased on the timeout_base argument change.

Cc: Lyude <cpaul@redhat.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Fixes: 656d1b89e5ff ("drm/i915/skl: Add support for the SAGV, fix underrun hangs")
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Lyude <lyude@redhat.com> (v4)
Link: http://patchwork.freedesktop.org/patch/msgid/1480955258-26311-2-git-send-email-imre.deak@intel.com
(cherry picked from commit b3b8e99984a4eace91bc097e8f8cec71441cae16)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/i915/intel_pm.c |   34 +++++++++-------------------------
 1 file changed, 9 insertions(+), 25 deletions(-)

--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -2955,24 +2955,10 @@ intel_enable_sagv(struct drm_i915_privat
 	return 0;
 }
 
-static int
-intel_do_sagv_disable(struct drm_i915_private *dev_priv)
-{
-	int ret;
-	uint32_t temp = GEN9_SAGV_DISABLE;
-
-	ret = sandybridge_pcode_read(dev_priv, GEN9_PCODE_SAGV_CONTROL,
-				     &temp);
-	if (ret)
-		return ret;
-	else
-		return temp & GEN9_SAGV_IS_DISABLED;
-}
-
 int
 intel_disable_sagv(struct drm_i915_private *dev_priv)
 {
-	int ret, result;
+	int ret;
 
 	if (!intel_has_sagv(dev_priv))
 		return 0;
@@ -2984,25 +2970,23 @@ intel_disable_sagv(struct drm_i915_priva
 	mutex_lock(&dev_priv->rps.hw_lock);
 
 	/* bspec says to keep retrying for at least 1 ms */
-	ret = wait_for(result = intel_do_sagv_disable(dev_priv), 1);
+	ret = skl_pcode_request(dev_priv, GEN9_PCODE_SAGV_CONTROL,
+				GEN9_SAGV_DISABLE,
+				GEN9_SAGV_IS_DISABLED, GEN9_SAGV_IS_DISABLED,
+				1);
 	mutex_unlock(&dev_priv->rps.hw_lock);
 
-	if (ret == -ETIMEDOUT) {
-		DRM_ERROR("Request to disable SAGV timed out\n");
-		return -ETIMEDOUT;
-	}
-
 	/*
 	 * Some skl systems, pre-release machines in particular,
 	 * don't actually have an SAGV.
 	 */
-	if (IS_SKYLAKE(dev_priv) && result == -ENXIO) {
+	if (IS_SKYLAKE(dev_priv) && ret == -ENXIO) {
 		DRM_DEBUG_DRIVER("No SAGV found on system, ignoring\n");
 		dev_priv->sagv_status = I915_SAGV_NOT_CONTROLLED;
 		return 0;
-	} else if (result < 0) {
-		DRM_ERROR("Failed to disable the SAGV\n");
-		return result;
+	} else if (ret < 0) {
+		DRM_ERROR("Failed to disable the SAGV (%d)\n", ret);
+		return ret;
 	}
 
 	dev_priv->sagv_status = I915_SAGV_DISABLED;


Patches currently in stable-queue which might be from imre.deak@intel.com are

queue-4.9/drm-i915-gen9-fix-pcode-polling-during-sagv-disabling.patch
queue-4.9/drm-i915-gen9-fix-pcode-polling-timeout-in-stable-backport.patch