From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Chris Wilson , Paulo Zanoni , Imre Deak , Daniel Vetter Subject: [PATCH 3.18 042/183] drm/i915: Only warn the first time we attempt to mmio whilst suspended Date: Sun, 25 Jan 2015 10:06:04 -0800 Message-Id: <20150125180812.002264160@linuxfoundation.org> In-Reply-To: <20150125180810.160428929@linuxfoundation.org> References: <20150125180810.160428929@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chris Wilson commit 2b387059817fd100cddc5a97118d63e3f3fade74 upstream. In all likelihood we will do a few hundred errnoneous register operations if we do a single invalid register access whilst the device is suspended. As each instance causes a WARN, this floods the system logs and can make the system unresponsive. The warning was first introduced in commit b2ec142cb0101f298f8e091c7d75b1ec5b809b65 Author: Paulo Zanoni Date: Fri Feb 21 13:52:25 2014 -0300 drm/i915: call assert_device_not_suspended at gen6_force_wake_work and despite the claims the WARN is still encountered in the wild today. Signed-off-by: Chris Wilson Cc: Paulo Zanoni Cc: Imre Deak Signed-off-by: Daniel Vetter Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i915/intel_uncore.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/gpu/drm/i915/intel_uncore.c +++ b/drivers/gpu/drm/i915/intel_uncore.c @@ -43,8 +43,8 @@ static void assert_device_not_suspended(struct drm_i915_private *dev_priv) { - WARN(HAS_RUNTIME_PM(dev_priv->dev) && dev_priv->pm.suspended, - "Device suspended\n"); + WARN_ONCE(HAS_RUNTIME_PM(dev_priv->dev) && dev_priv->pm.suspended, + "Device suspended\n"); } static void __gen6_gt_wait_for_thread_c0(struct drm_i915_private *dev_priv)