From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jesse Barnes <jbarnes@virtuousgeek.org>
Subject: Re: [Intel-gfx] [PATCH] drm/i915: fix long-standing SNB regression
 in power consumption after resume
Date: Tue, 16 Jul 2013 13:19:25 -0700
Message-ID: <20130716131925.7997a7ed@jbarnes-desktop>
References: <20130714163009.22374.22100.stgit@zurg>
	<CAKMK7uEtReZxvzJj9LsSXEJEBNiK492CCONdsF5VFK2cA3u0FA@mail.gmail.com>
	<51E2E65D.5050803@openvz.org>
	<20130716063101.GK5784@phenom.ffwll.local>
	<CALYGNiOtt7FUCTqcyBELoHYEVw_zqmA=bpmHy_nDkhXCduB9qg@mail.gmail.com>
	<20130716100654.1185c031@jbarnes-desktop>
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Return-path: <linux-kernel-owner@vger.kernel.org>
In-Reply-To: <20130716100654.1185c031@jbarnes-desktop>
Sender: linux-kernel-owner@vger.kernel.org
To: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>, David Airlie <airlied@linux.ie>, Daniel Vetter <daniel.vetter@ffwll.ch>, intel-gfx <intel-gfx@lists.freedesktop.org>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, dri-devel <dri-devel@lists.freedesktop.org>, Alexander Kaltsas <alexkaltsas@gmail.com>, rocko <rockorequin@hotmail.com>
List-Id: dri-devel@lists.freedesktop.org

On Tue, 16 Jul 2013 10:06:54 -0700
Jesse Barnes <jbarnes@virtuousgeek.org> wrote:

> On Tue, 16 Jul 2013 11:34:25 +0400
> Konstantin Khlebnikov <khlebnikov@openvz.org> wrote:
> > I've tested that patch and it really works for me. If you want change
> > something for other hardware or
> > extend range where forcewake is held prease do it in a separate patch.
> > This will be good for bisecting new bugs in the future.
> 
> Thanks a ton for finding this Konstantin, it puts us on the right
> track.
> 
> Can I ask you to test this patch?  The theory is that having RC6
> enabled messes with the initial programming sequence, so it's probably
> best to just shut it off at init until we're done, rather than trying
> to forcewake around everywhere we need it.

Oops, last one triggers a warn about IRQs.  This one doesn't and still
works for me.

Testing welcome.

Thanks,
-- 
Jesse Barnes, Intel Open Source Technology Center

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index c9d9d20..d962ec0 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4112,6 +4112,9 @@ i915_gem_init_hw(struct drm_device *dev)
        drm_i915_private_t *dev_priv = dev->dev_private;
        int ret;
 
+       /* BIOS often leaves RC6 enabled, but disable it for hw init */
+       intel_disable_gt_powersave(dev);
+
        if (INTEL_INFO(dev)->gen < 6 && !intel_enable_gtt())
                return -EIO;