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>

4 files changed, 13 insertions, 14 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_drv.h b/drivers/gpu/drm/nouveau/nouveau_drv.h
index 1c6279f588ba..2e3d7fb4912a 100644
--- a/drivers/gpu/drm/nouveau/nouveau_drv.h
+++ b/drivers/gpu/drm/nouveau/nouveau_drv.h
@@ -652,7 +652,6 @@ struct drm_nouveau_private {
         /* interrupt handling */
         void (*irq_handler[32])(struct drm_device *);
         bool msi_enabled;
-        struct workqueue_struct *wq;
         struct work_struct irq_work;
 
         struct list_head vbl_waiting;
diff --git a/drivers/gpu/drm/nouveau/nouveau_state.c b/drivers/gpu/drm/nouveau/nouveau_state.c
index 2148d01354da..805c0b3fcdb7 100644
--- a/drivers/gpu/drm/nouveau/nouveau_state.c
+++ b/drivers/gpu/drm/nouveau/nouveau_state.c
@@ -929,12 +929,6 @@ int nouveau_load(struct drm_device *dev, unsigned long flags)
         NV_DEBUG(dev, "vendor: 0x%X device: 0x%X class: 0x%X\n",
                  dev->pci_vendor, dev->pci_device, dev->pdev->class);
 
-        dev_priv->wq = create_workqueue("nouveau");
-        if (!dev_priv->wq) {
-                ret = -EINVAL;
-                goto err_priv;
-        }
-
         /* resource 0 is mmio regs */
         /* resource 1 is linear FB */
         /* resource 2 is RAMIN (mmio regs + 0x1000000) */
@@ -947,7 +941,7 @@ int nouveau_load(struct drm_device *dev, unsigned long flags)
                 NV_ERROR(dev, "Unable to initialize the mmio mapping. "
                          "Please report your setup to " DRIVER_EMAIL "\n");
                 ret = -EINVAL;
-                goto err_wq;
+                goto err_priv;
         }
         NV_DEBUG(dev, "regs mapped ok at 0x%llx\n",
                                         (unsigned long long)mmio_start_offs);
@@ -1054,8 +1048,6 @@ err_ramin:
         iounmap(dev_priv->ramin);
 err_mmio:
         iounmap(dev_priv->mmio);
-err_wq:
-        destroy_workqueue(dev_priv->wq);
 err_priv:
         kfree(dev_priv);
         dev->dev_private = NULL;
diff --git a/drivers/gpu/drm/nouveau/nv50_display.c b/drivers/gpu/drm/nouveau/nv50_display.c
index 5096f2f45df8..a804a350800e 100644
--- a/drivers/gpu/drm/nouveau/nv50_display.c
+++ b/drivers/gpu/drm/nouveau/nv50_display.c
@@ -345,12 +345,15 @@ int nv50_display_create(struct drm_device *dev)
 void
 nv50_display_destroy(struct drm_device *dev)
 {
+        struct drm_nouveau_private *dev_priv = dev->dev_private;
+
         NV_DEBUG_KMS(dev, "\n");
 
         drm_mode_config_cleanup(dev);
 
         nv50_display_disable(dev);
         nouveau_irq_unregister(dev, 26);
+        flush_work_sync(&dev_priv->irq_work);
 }
 
 static u16
@@ -836,7 +839,7 @@ nv50_display_isr(struct drm_device *dev)
                 if (clock) {
                         nv_wr32(dev, NV03_PMC_INTR_EN_0, 0);
                         if (!work_pending(&dev_priv->irq_work))
-                                queue_work(dev_priv->wq, &dev_priv->irq_work);
+                                schedule_work(&dev_priv->irq_work);
                         delayed |= clock;
                         intr1 &= ~clock;
                 }
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);
 }