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

This reverts commit 747dba7de2.

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: Hans Verkuil <hans.verkuil@cisco.com>
Tested-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
This commit is contained in:
Frank Schaefer 2014-09-18 17:55:45 -03:00 committed by Mauro Carvalho Chehab
parent c7854c2c5d
commit 8e2c8717c1
2 changed files with 11 additions and 13 deletions
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23
drivers/media/usb/em28xx/em28xx-video.c
View File

@ -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;
em28xx_videodbg("users=%d\n", v4l2->users);
vb2_fop_release(filp);
mutex_lock(&dev->lock);
if (v4l2_fh_is_singular_file(filp)) {
em28xx_videodbg("last opened filehandle, shutting down device\n");
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);

1
drivers/media/usb/em28xx/em28xx.h
View File

@ -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 */