drm/nouveau/drm/nouveau: Fix deadlock with fb_helper with async RPM requests

author Lyude Paul <lyude@redhat.com>

Wed, 15 Aug 2018 19:00:13 +0000 (15:00 -0400)

committer Ben Skeggs <bskeggs@redhat.com>

Thu, 6 Sep 2018 20:54:26 +0000 (06:54 +1000)
author Lyude Paul <lyude@redhat.com>
Wed, 15 Aug 2018 19:00:13 +0000 (15:00 -0400)
committer Ben Skeggs <bskeggs@redhat.com>
Thu, 6 Sep 2018 20:54:26 +0000 (06:54 +1000)
diff --git a/drivers/gpu/drm/nouveau/dispnv50/disp.c b/drivers/gpu/drm/nouveau/dispnv50/disp.c

index 8412119..aec6ee1 100644 (file)
--- a/drivers/gpu/drm/nouveau/dispnv50/disp.c
+++ b/drivers/gpu/drm/nouveau/dispnv50/disp.c
@@ -2074,7 +2074,7 @@ nv50_disp_atomic_state_alloc(struct drm_device *dev)
  static const struct drm_mode_config_funcs
  nv50_disp_func = {
         .fb_create = nouveau_user_framebuffer_create,
-       .output_poll_changed = drm_fb_helper_output_poll_changed,
+       .output_poll_changed = nouveau_fbcon_output_poll_changed,
         .atomic_check = nv50_disp_atomic_check,
         .atomic_commit = nv50_disp_atomic_commit,
         .atomic_state_alloc = nv50_disp_atomic_state_alloc,
diff --git a/drivers/gpu/drm/nouveau/nouveau_display.c b/drivers/gpu/drm/nouveau/nouveau_display.c

index 7db01ea..42e7c35 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_display.c
+++ b/drivers/gpu/drm/nouveau/nouveau_display.c
@@ -293,7 +293,7 @@ nouveau_user_framebuffer_create(struct drm_device *dev,
  
  static const struct drm_mode_config_funcs nouveau_mode_config_funcs = {
         .fb_create = nouveau_user_framebuffer_create,
-       .output_poll_changed = drm_fb_helper_output_poll_changed,
+       .output_poll_changed = nouveau_fbcon_output_poll_changed,
  };
  
  
diff --git a/drivers/gpu/drm/nouveau/nouveau_fbcon.c b/drivers/gpu/drm/nouveau/nouveau_fbcon.c

index 844498c..0f64c0a 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_fbcon.c
+++ b/drivers/gpu/drm/nouveau/nouveau_fbcon.c
@@ -466,6 +466,7 @@ nouveau_fbcon_set_suspend_work(struct work_struct *work)
         console_unlock();
  
         if (state == FBINFO_STATE_RUNNING) {
+               nouveau_fbcon_hotplug_resume(drm->fbcon);
                 pm_runtime_mark_last_busy(drm->dev->dev);
                 pm_runtime_put_sync(drm->dev->dev);
         }
@@ -487,6 +488,61 @@ nouveau_fbcon_set_suspend(struct drm_device *dev, int state)
         schedule_work(&drm->fbcon_work);
  }
  
+void
+nouveau_fbcon_output_poll_changed(struct drm_device *dev)
+{
+       struct nouveau_drm *drm = nouveau_drm(dev);
+       struct nouveau_fbdev *fbcon = drm->fbcon;
+       int ret;
+
+       if (!fbcon)
+               return;
+
+       mutex_lock(&fbcon->hotplug_lock);
+
+       ret = pm_runtime_get(dev->dev);
+       if (ret == 1 || ret == -EACCES) {
+               drm_fb_helper_hotplug_event(&fbcon->helper);
+
+               pm_runtime_mark_last_busy(dev->dev);
+               pm_runtime_put_autosuspend(dev->dev);
+       } else if (ret == 0) {
+               /* If the GPU was already in the process of suspending before
+                * this event happened, then we can't block here as we'll
+                * deadlock the runtime pmops since they wait for us to
+                * finish. So, just defer this event for when we runtime
+                * resume again. It will be handled by fbcon_work.
+                */
+               NV_DEBUG(drm, "fbcon HPD event deferred until runtime resume\n");
+               fbcon->hotplug_waiting = true;
+               pm_runtime_put_noidle(drm->dev->dev);
+       } else {
+               DRM_WARN("fbcon HPD event lost due to RPM failure: %d\n",
+                        ret);
+       }
+
+       mutex_unlock(&fbcon->hotplug_lock);
+}
+
+void
+nouveau_fbcon_hotplug_resume(struct nouveau_fbdev *fbcon)
+{
+       struct nouveau_drm *drm;
+
+       if (!fbcon)
+               return;
+       drm = nouveau_drm(fbcon->helper.dev);
+
+       mutex_lock(&fbcon->hotplug_lock);
+       if (fbcon->hotplug_waiting) {
+               fbcon->hotplug_waiting = false;
+
+               NV_DEBUG(drm, "Handling deferred fbcon HPD events\n");
+               drm_fb_helper_hotplug_event(&fbcon->helper);
+       }
+       mutex_unlock(&fbcon->hotplug_lock);
+}
+
  int
  nouveau_fbcon_init(struct drm_device *dev)
  {
@@ -505,6 +561,7 @@ nouveau_fbcon_init(struct drm_device *dev)
  
         drm->fbcon = fbcon;
         INIT_WORK(&drm->fbcon_work, nouveau_fbcon_set_suspend_work);
+       mutex_init(&fbcon->hotplug_lock);
  
         drm_fb_helper_prepare(dev, &fbcon->helper, &nouveau_fbcon_helper_funcs);
  
diff --git a/drivers/gpu/drm/nouveau/nouveau_fbcon.h b/drivers/gpu/drm/nouveau/nouveau_fbcon.h

index a6f192e..db9d520 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_fbcon.h
+++ b/drivers/gpu/drm/nouveau/nouveau_fbcon.h
@@ -41,6 +41,9 @@ struct nouveau_fbdev {
         struct nvif_object gdi;
         struct nvif_object blit;
         struct nvif_object twod;
+
+       struct mutex hotplug_lock;
+       bool hotplug_waiting;
  };
  
  void nouveau_fbcon_restore(void);
@@ -68,6 +71,8 @@ void nouveau_fbcon_set_suspend(struct drm_device *dev, int state);
  void nouveau_fbcon_accel_save_disable(struct drm_device *dev);
  void nouveau_fbcon_accel_restore(struct drm_device *dev);
  
+void nouveau_fbcon_output_poll_changed(struct drm_device *dev);
+void nouveau_fbcon_hotplug_resume(struct nouveau_fbdev *fbcon);
  extern int nouveau_nofbaccel;
  
  #endif /* __NV50_FBCON_H__ */
author	Lyude Paul <lyude@redhat.com>
	Wed, 15 Aug 2018 19:00:13 +0000 (15:00 -0400)
committer	Ben Skeggs <bskeggs@redhat.com>
	Thu, 6 Sep 2018 20:54:26 +0000 (06:54 +1000)
drivers/gpu/drm/nouveau/dispnv50/disp.c		patch \| blob \| history
drivers/gpu/drm/nouveau/nouveau_display.c		patch \| blob \| history
drivers/gpu/drm/nouveau/nouveau_fbcon.c		patch \| blob \| history
drivers/gpu/drm/nouveau/nouveau_fbcon.h		patch \| blob \| history