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 <paulo.r.zanoni@xxxxxxxxx> 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 <chris@xxxxxxxxxxxxxxxxxx> Cc: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx> Cc: Imre Deak <imre.deak@xxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx --- drivers/gpu/drm/i915/intel_uncore.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c index 1a3e485a4f97..f0230b0e8e11 100644 --- 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) -- 2.1.3 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html