Commit 44f70338 authored by Ricardo Ribalda's avatar Ricardo Ribalda Committed by Hans Verkuil
Browse files

media: uvcvideo: Refactor the status irq API 



There are two different use-cases of uvc_status():

- adding/removing a user when the camera is open/closed
- stopping/starting when the camera is suspended/resumed

Make the API reflect these two use-cases and move all the refcounting
and locking logic to the uvc_status.c file.

No functional change is expected from this patch.

Reviewed-by: default avatarSergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: default avatarRicardo Ribalda <ribalda@chromium.org>
Reviewed-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://lore.kernel.org/r/20240926-guenter-mini-v7-1-690441953d4a@chromium.org


Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarHans Verkuil <hverkuil-cisco@xs4all.nl>
parent 3dd075fe

drivers/media/usb/uvc/uvc_driver.c

+2 −11
Original line number Diff line number Diff line
@@ -2132,7 +2132,6 @@ static int uvc_probe(struct usb_interface *intf, 
	INIT_LIST_HEAD(&dev->streams);

	kref_init(&dev->ref);

	atomic_set(&dev->nmappings, 0);

	mutex_init(&dev->lock);



	dev->udev = usb_get_dev(udev);

	dev->intf = usb_get_intf(intf);
@@ -2304,10 +2303,7 @@ static int uvc_suspend(struct usb_interface *intf, pm_message_t message) 
	/* Controls are cached on the fly so they don't need to be saved. */

	if (intf->cur_altsetting->desc.bInterfaceSubClass ==

	    UVC_SC_VIDEOCONTROL) {

		mutex_lock(&dev->lock);

		if (dev->users)

			uvc_status_stop(dev);

		mutex_unlock(&dev->lock);

		uvc_status_suspend(dev);

		return 0;

	}
@@ -2338,12 +2334,7 @@ static int __uvc_resume(struct usb_interface *intf, int reset) 
				return ret;

		}



		mutex_lock(&dev->lock);

		if (dev->users)

			ret = uvc_status_start(dev, GFP_NOIO);

		mutex_unlock(&dev->lock);



		return ret;

		return uvc_status_resume(dev);

	}



	list_for_each_entry(stream, &dev->streams, list) {

drivers/media/usb/uvc/uvc_status.c

+54 −2
Original line number Diff line number Diff line
@@ -257,6 +257,8 @@ int uvc_status_init(struct uvc_device *dev) 
	unsigned int pipe;

	int interval;



	mutex_init(&dev->status_lock);



	if (ep == NULL)

		return 0;
@@ -302,18 +304,22 @@ void uvc_status_cleanup(struct uvc_device *dev) 
	kfree(dev->status);

}



int uvc_status_start(struct uvc_device *dev, gfp_t flags)

static int uvc_status_start(struct uvc_device *dev, gfp_t flags)

{

	lockdep_assert_held(&dev->status_lock);



	if (dev->int_urb == NULL)

		return 0;



	return usb_submit_urb(dev->int_urb, flags);

}



void uvc_status_stop(struct uvc_device *dev)

static void uvc_status_stop(struct uvc_device *dev)

{

	struct uvc_ctrl_work *w = &dev->async_ctrl;



	lockdep_assert_held(&dev->status_lock);



	/*

	 * Prevent the asynchronous control handler from requeing the URB. The

	 * barrier is needed so the flush_status change is visible to other
@@ -350,3 +356,49 @@ void uvc_status_stop(struct uvc_device *dev) 
	 */

	smp_store_release(&dev->flush_status, false);

}



int uvc_status_resume(struct uvc_device *dev)

{

	guard(mutex)(&dev->status_lock);



	if (dev->status_users)

		return uvc_status_start(dev, GFP_NOIO);



	return 0;

}



void uvc_status_suspend(struct uvc_device *dev)

{

	guard(mutex)(&dev->status_lock);



	if (dev->status_users)

		uvc_status_stop(dev);

}



int uvc_status_get(struct uvc_device *dev)

{

	int ret;



	guard(mutex)(&dev->status_lock);



	if (!dev->status_users) {

		ret = uvc_status_start(dev, GFP_KERNEL);

		if (ret)

			return ret;

	}



	dev->status_users++;



	return 0;

}



void uvc_status_put(struct uvc_device *dev)

{

	guard(mutex)(&dev->status_lock);



	if (dev->status_users == 1)

		uvc_status_stop(dev);

	WARN_ON(!dev->status_users);

	if (dev->status_users)

		dev->status_users--;

}

drivers/media/usb/uvc/uvc_v4l2.c

+6 −16
Original line number Diff line number Diff line
@@ -628,19 +628,12 @@ static int uvc_v4l2_open(struct file *file) 
		return -ENOMEM;

	}



	mutex_lock(&stream->dev->lock);

	if (stream->dev->users == 0) {

		ret = uvc_status_start(stream->dev, GFP_KERNEL);

		if (ret < 0) {

			mutex_unlock(&stream->dev->lock);

	ret = uvc_status_get(stream->dev);

	if (ret) {

		usb_autopm_put_interface(stream->dev->intf);

		kfree(handle);

		return ret;

	}

	}



	stream->dev->users++;

	mutex_unlock(&stream->dev->lock);



	v4l2_fh_init(&handle->vfh, &stream->vdev);

	v4l2_fh_add(&handle->vfh);
@@ -670,10 +663,7 @@ static int uvc_v4l2_release(struct file *file) 
	kfree(handle);

	file->private_data = NULL;



	mutex_lock(&stream->dev->lock);

	if (--stream->dev->users == 0)

		uvc_status_stop(stream->dev);

	mutex_unlock(&stream->dev->lock);

	uvc_status_put(stream->dev);



	usb_autopm_put_interface(stream->dev->intf);

	return 0;

drivers/media/usb/uvc/uvcvideo.h

+6 −4
Original line number Diff line number Diff line
@@ -563,8 +563,6 @@ struct uvc_device { 


	const struct uvc_device_info *info;



	struct mutex lock;		/* Protects users */

	unsigned int users;

	atomic_t nmappings;



	/* Video control interface */
@@ -586,6 +584,8 @@ struct uvc_device { 
	struct usb_host_endpoint *int_ep;

	struct urb *int_urb;

	struct uvc_status *status;

	struct mutex status_lock; /* Protects status_users */

	unsigned int status_users;

	bool flush_status;



	struct input_dev *input;
@@ -752,8 +752,10 @@ int uvc_register_video_device(struct uvc_device *dev, 
int uvc_status_init(struct uvc_device *dev);

void uvc_status_unregister(struct uvc_device *dev);

void uvc_status_cleanup(struct uvc_device *dev);

int uvc_status_start(struct uvc_device *dev, gfp_t flags);

void uvc_status_stop(struct uvc_device *dev);

int uvc_status_resume(struct uvc_device *dev);

void uvc_status_suspend(struct uvc_device *dev);

int uvc_status_get(struct uvc_device *dev);

void uvc_status_put(struct uvc_device *dev);



/* Controls */

extern const struct v4l2_subscribed_event_ops uvc_ctrl_sub_ev_ops;