[media] pwc: convert to core-assisted locking

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/pwc/pwc-if.c

@@ -1098,7 +1098,6 @@ static int pwc_video_open(struct file *file)
 		return -EBUSY;
 	}
 
-	mutex_lock(&pdev->modlock);
 	pwc_construct(pdev); /* set min/max sizes correct */
 	if (!pdev->usb_init) {
 		PWC_DEBUG_OPEN("Doing first time initialization.\n");
@@ -1130,7 +1129,6 @@ static int pwc_video_open(struct file *file)
 	if (i < 0) {
 		PWC_DEBUG_OPEN("Failed to allocate buffers memory.\n");
 		pwc_free_buffers(pdev);
-		mutex_unlock(&pdev->modlock);
 		return i;
 	}
 
@@ -1171,7 +1169,6 @@ static int pwc_video_open(struct file *file)
 	if (i) {
 		PWC_DEBUG_OPEN("Second attempt at set_video_mode failed.\n");
 		pwc_free_buffers(pdev);
-		mutex_unlock(&pdev->modlock);
 		return i;
 	}
 
@@ -1181,7 +1178,6 @@ static int pwc_video_open(struct file *file)
 
 	pdev->vopen++;
 	file->private_data = vdev;
-	mutex_unlock(&pdev->modlock);
 	PWC_DEBUG_OPEN("<< video_open() returns 0.\n");
 	return 0;
 }
@@ -1210,7 +1206,6 @@ static int pwc_video_close(struct file *file)
 	PWC_DEBUG_OPEN(">> video_close called(vdev = 0x%p).\n", vdev);
 
 	pdev = video_get_drvdata(vdev);
-	mutex_lock(&pdev->modlock);
 	if (pdev->vopen == 0)
 		PWC_DEBUG_MODULE("video_close() called on closed device?\n");
 
@@ -1248,7 +1243,6 @@ static int pwc_video_close(struct file *file)
 			if (device_hint[hint].pdev == pdev)
 				device_hint[hint].pdev = NULL;
 	}
-	mutex_unlock(&pdev->modlock);
 
 	return 0;
 }
@@ -1283,7 +1277,6 @@ static ssize_t pwc_video_read(struct file *file, char __user *buf,
 	if (pdev == NULL)
 		return -EFAULT;
 
-	mutex_lock(&pdev->modlock);
 	if (pdev->error_status) {
 		rv = -pdev->error_status; /* Something happened, report what. */
 		goto err_out;
@@ -1318,8 +1311,10 @@ static ssize_t pwc_video_read(struct file *file, char __user *buf,
 				rv = -ERESTARTSYS;
 				goto err_out;
 			}
+			mutex_unlock(&pdev->modlock);
 			schedule();
 			set_current_state(TASK_INTERRUPTIBLE);
+			mutex_lock(&pdev->modlock);
 		}
 		remove_wait_queue(&pdev->frameq, &wait);
 		set_current_state(TASK_RUNNING);
@@ -1352,10 +1347,8 @@ static ssize_t pwc_video_read(struct file *file, char __user *buf,
 		pdev->image_read_pos = 0;
 		pwc_next_image(pdev);
 	}
-	mutex_unlock(&pdev->modlock);
 	return count;
 err_out:
-	mutex_unlock(&pdev->modlock);
 	return rv;
 }
 
@@ -1372,9 +1365,7 @@ static unsigned int pwc_video_poll(struct file *file, poll_table *wait)
 		return -EFAULT;
 
 	/* Start the stream (if not already started) */
-	mutex_lock(&pdev->modlock);
 	ret = pwc_isoc_init(pdev);
-	mutex_unlock(&pdev->modlock);
 	if (ret)
 		return ret;
 
@@ -1398,10 +1389,8 @@ static long pwc_video_ioctl(struct file *file,
 		goto out;
 	pdev = video_get_drvdata(vdev);
 
-	mutex_lock(&pdev->modlock);
 	if (!pdev->unplugged)
 		r = video_usercopy(file, cmd, arg, pwc_video_do_ioctl);
-	mutex_unlock(&pdev->modlock);
 out:
 	return r;
 }
@@ -1754,6 +1743,7 @@ static int usb_pwc_probe(struct usb_interface *intf, const struct usb_device_id
 	}
 	memcpy(pdev->vdev, &pwc_template, sizeof(pwc_template));
 	pdev->vdev->parent = &intf->dev;
+	pdev->vdev->lock = &pdev->modlock;
 	strcpy(pdev->vdev->name, name);
 	video_set_drvdata(pdev->vdev, pdev);
 

drivers/media/video/pwc/pwc-v4l.c

@@ -830,8 +830,10 @@ long pwc_video_do_ioctl(struct file *file, unsigned int cmd, void *arg)
 					set_current_state(TASK_RUNNING);
 					return -ERESTARTSYS;
 				}
+				mutex_unlock(&pdev->modlock);
 				schedule();
 				set_current_state(TASK_INTERRUPTIBLE);
+				mutex_lock(&pdev->modlock);
 			}
 			remove_wait_queue(&pdev->frameq, &wait);
 			set_current_state(TASK_RUNNING);