We need it to restore the ilk rc6 context, since the gpu wait no requires interrupts. But in general having interrupts around should help in code sanity, since more and more stuff is interrupt driven. This regression has been introduced in commit 3e9605018ab3e333d51cc90fccfde2031886763b Author: Chris Wilson <chris at chris-wilson.co.uk> Date: Tue Nov 27 16:22:54 2012 +0000 drm/i915: Rearrange code to only have a single method for waiting upon the ring Like in the driver load code we need to make sure that hotplug interrupts don't cause havoc with our modeset state, hence block them with the existing infrastructure. Again we ignore races where we might loose hotplug interrupts ... Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=54691 Cc: stable at vger.kernel.org (for 3.8 only) Cc: Chris Wilson <chris at chris-wilson.co.uk> Cc: Mika Kuoppala <mika.kuoppala at intel.com> Reported-and-Tested-by: Ilya Tumaykin <itumaykin at gmail.com> Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch> --- drivers/gpu/drm/i915/i915_drv.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index b342749..7589a2a 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -493,6 +493,7 @@ static int i915_drm_freeze(struct drm_device *dev) intel_modeset_disable(dev); drm_irq_uninstall(dev); + dev_priv->enable_hotplug_processing = false; } i915_save_state(dev); @@ -566,10 +567,20 @@ static int __i915_drm_thaw(struct drm_device *dev) error = i915_gem_init_hw(dev); mutex_unlock(&dev->struct_mutex); + /* We need working interrupts for modeset enabling ... */ + drm_irq_install(dev); + intel_modeset_init_hw(dev); intel_modeset_setup_hw_state(dev, false); - drm_irq_install(dev); + + /* + * ... but also need to make sure that hotplug processing + * doesn't cause havoc. Like in the driver load code we don't + * bother with the tiny race here where we might loose hotplug + * notifications. + * */ intel_hpd_init(dev); + dev_priv->enable_hotplug_processing = true; } intel_opregion_init(dev); -- 1.7.10.4