drm/nouveau: use system_wq instead of dev_priv->wq

With cmwq, there's no reason for nouveau to use a dedicated workqueue.
Drop dev_priv->wq and use system_wq instead.  Each work item is sync
flushed when the containing structure is unregistered/destroyed.

Note that this change also makes sure that nv50_gpio_handler is not
freed while the contained work item is still running.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: David Airlie <airlied@linux.ie>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 8 insertions, 3 deletions

diff --git a/drivers/gpu/drm/nouveau/nv50_gpio.c b/drivers/gpu/drm/nouveau/nv50_gpio.c
index 1710c080272f..d4f4206dad7e 100644
--- a/drivers/gpu/drm/nouveau/nv50_gpio.c
+++ b/drivers/gpu/drm/nouveau/nv50_gpio.c
@@ -137,6 +137,7 @@ nv50_gpio_irq_unregister(struct drm_device *dev, enum dcb_gpio_tag tag,
 	struct nv50_gpio_priv *priv = pgpio->priv;
 	struct nv50_gpio_handler *gpioh, *tmp;
 	struct dcb_gpio_entry *gpio;
+	LIST_HEAD(tofree);
 	unsigned long flags;
 
 	gpio = nouveau_bios_gpio_entry(dev, tag);
@@ -149,10 +150,14 @@ nv50_gpio_irq_unregister(struct drm_device *dev, enum dcb_gpio_tag tag,
 		    gpioh->handler != handler ||
 		    gpioh->data != data)
 			continue;
-		list_del(&gpioh->head);
-		kfree(gpioh);
+		list_move(&gpioh->head, &tofree);
 	}
 	spin_unlock_irqrestore(&priv->lock, flags);
+
+	list_for_each_entry_safe(gpioh, tmp, &tofree, head) {
+		flush_work_sync(&gpioh->work);
+		kfree(gpioh);
+	}
 }
 
 bool
@@ -291,7 +296,7 @@ nv50_gpio_isr(struct drm_device *dev)
 			continue;
 		gpioh->inhibit = true;
 
-		queue_work(dev_priv->wq, &gpioh->work);
+		schedule_work(&gpioh->work);
 	}
 	spin_unlock(&priv->lock);
 }