Commit 8e2c8717 authored by Frank Schaefer's avatar Frank Schaefer Committed by Mauro Carvalho Chehab
Browse files

[media] em28xx-v4l: get rid of field "users" in struct em28xx_v4l2" 



This reverts commit 747dba7d.

It breaks concurrent vbi and video capturing:
While v4l2->users is the number of users of the whole device (all device nodes),
v4l2_fh_is_singular() only checks the number of users of a specific device node.
As a result. if one device node is open and a second device node is opened
(closed), the device is reinitialized (streaming is stopped).

Reported-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
Tested-by: default avatarMauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: default avatarFrank Schäfer <fschaefer.oss@googlemail.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@osg.samsung.com>
parent c7854c2c

drivers/media/usb/em28xx/em28xx-video.c

+10 −13
Original line number Diff line number Diff line
@@ -1883,8 +1883,9 @@ static int em28xx_v4l2_open(struct file *filp) 
		return -EINVAL;

	}



	em28xx_videodbg("open dev=%s type=%s\n",

			video_device_node_name(vdev), v4l2_type_names[fh_type]);

	em28xx_videodbg("open dev=%s type=%s users=%d\n",

			video_device_node_name(vdev), v4l2_type_names[fh_type],

			v4l2->users);



	if (mutex_lock_interruptible(&dev->lock))

		return -ERESTARTSYS;
@@ -1897,9 +1898,7 @@ static int em28xx_v4l2_open(struct file *filp) 
		return ret;

	}



	if (v4l2_fh_is_singular_file(filp)) {

		em28xx_videodbg("first opened filehandle, initializing device\n");



	if (v4l2->users == 0) {

		em28xx_set_mode(dev, EM28XX_ANALOG_MODE);



		if (vdev->vfl_type != VFL_TYPE_RADIO)
@@ -1910,8 +1909,6 @@ static int em28xx_v4l2_open(struct file *filp) 
		 * of some i2c devices

		 */

		em28xx_wake_i2c(dev);

	} else {

		em28xx_videodbg("further filehandles are already opened\n");

	}



	if (vdev->vfl_type == VFL_TYPE_RADIO) {
@@ -1921,6 +1918,7 @@ static int em28xx_v4l2_open(struct file *filp) 


	kref_get(&dev->ref);

	kref_get(&v4l2->ref);

	v4l2->users++;



	mutex_unlock(&dev->lock);
@@ -2027,11 +2025,12 @@ static int em28xx_v4l2_close(struct file *filp) 
	struct em28xx_v4l2    *v4l2 = dev->v4l2;

	int              errCode;



	mutex_lock(&dev->lock);

	em28xx_videodbg("users=%d\n", v4l2->users);



	if (v4l2_fh_is_singular_file(filp)) {

		em28xx_videodbg("last opened filehandle, shutting down device\n");

	vb2_fop_release(filp);

	mutex_lock(&dev->lock);



	if (v4l2->users == 1) {

		/* No sense to try to write to the device */

		if (dev->disconnected)

			goto exit;
@@ -2050,12 +2049,10 @@ static int em28xx_v4l2_close(struct file *filp) 
			em28xx_errdev("cannot change alternate number to "

					"0 (error=%i)\n", errCode);

		}

	} else {

		em28xx_videodbg("further opened filehandles left\n");

	}



exit:

	vb2_fop_release(filp);

	v4l2->users--;

	kref_put(&v4l2->ref, em28xx_free_v4l2);

	mutex_unlock(&dev->lock);

	kref_put(&dev->ref, em28xx_free_device);

drivers/media/usb/em28xx/em28xx.h

+1 −0
Original line number Diff line number Diff line
@@ -524,6 +524,7 @@ struct em28xx_v4l2 { 
	int sensor_yres;

	int sensor_xtal;



	int users;		/* user count for exclusive use */

	int streaming_users;    /* number of actively streaming users */



	u32 frequency;		/* selected tuner frequency */

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