drm/i915: disable interrupts earlier in the driver unload code

Our rps code relies on the interrupts being off to prevent re-arming
of the work items at inopportune moments.

Also drop the redundant cancel_work for the main rps work,
disable_gt_powersave already takes care of that.

Finally add a WARN_ON to ensure we obey that piece of ordering
constraint. Long term I want to lock down the setup/teardown code in a
similar way to how we painstakingly check modeset sequence constraints
already.

v2: Disable polling after hpd handling is shut down - since Egbert's
hpd irq storm handling the hotplug work can re-arm the polling
handler. Spotted by Jani Nikula.

Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 74156e231fd57f739f0f4d1bf6e2b6fe50a7ffcf..988e543ec45bfa65f717eb6f3eb844b44ac932a3 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -9530,12 +9530,23 @@ void intel_modeset_cleanup(struct drm_device *dev)
        struct drm_crtc *crtc;
        struct intel_crtc *intel_crtc;
 
+       /*
+        * Interrupts and polling as the first thing to avoid creating havoc.
+        * Too much stuff here (turning of rps, connectors, ...) would
+        * experience fancy races otherwise.
+        */
+       drm_irq_uninstall(dev);
+       cancel_work_sync(&dev_priv->hotplug_work);
+       /*
+        * Due to the hpd irq storm handling the hotplug work can re-arm the
+        * poll handlers. Hence disable polling after hpd handling is shut down.
+        */
        drm_kms_helper_poll_fini(dev);
+
        mutex_lock(&dev->struct_mutex);
 
        intel_unregister_dsm_handler();
 
-
        list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
                /* Skip inactive CRTCs */
                if (!crtc->fb)
@@ -9553,12 +9564,6 @@ void intel_modeset_cleanup(struct drm_device *dev)
 
        mutex_unlock(&dev->struct_mutex);
 
-       /* Disable the irq before mode object teardown, for the irq might
-        * enqueue unpin/hotplug work. */
-       drm_irq_uninstall(dev);
-       cancel_work_sync(&dev_priv->hotplug_work);
-       cancel_work_sync(&dev_priv->rps.work);
-
        /* flush any delayed tasks or pending work */
        flush_scheduled_work();
 

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 8b7f050decdd7d04f54116cf06b29f569b40362a..bb45122173dd1b830abcf80c4cc4071cf9971b97 100644 (file)
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3671,6 +3671,9 @@ void intel_disable_gt_powersave(struct drm_device *dev)
 {
        struct drm_i915_private *dev_priv = dev->dev_private;
 
+       /* Interrupts should be disabled already to avoid re-arming. */
+       WARN_ON(dev->irq_enabled);
+
        if (IS_IRONLAKE_M(dev)) {
                ironlake_disable_drps(dev);
                ironlake_disable_rc6(dev);