Hi Hans, Am 18.09.2014 um 21:13 schrieb Hans Verkuil: > Hi Frank, > > On 07/25/2014 07:48 PM, Frank Schäfer wrote: >> Instead of counting the number of opened file handles, use function >> v4l2_fh_is_singular_file() in em28xx_v4l2_open() and em28xx_v4l2_close() to >> determine if the file handle is the first/last opened one. > This won't work: if you capture from both /dev/video and /dev/vbi and close > one, then it stops all streaming. You are 100% right, v4l2_fh_is_singular() is a per device _node_ check. How could I miss that ? :/
> I would just revert this patch completely. > > There is currently no core support for detecting when all users of all devices > registered by a driver have left, so you don't have really have an alternative > but to use your old code. Indeed. I will send a revert patch. Thanks for the hint ! Regards, Frank > > Regards, > > Hans > >> Signed-off-by: Frank Schäfer <[email protected]> >> --- >> drivers/media/usb/em28xx/em28xx-video.c | 23 +++++++++++++---------- >> drivers/media/usb/em28xx/em28xx.h | 1 - >> 2 files changed, 13 insertions(+), 11 deletions(-) >> >> diff --git a/drivers/media/usb/em28xx/em28xx-video.c >> b/drivers/media/usb/em28xx/em28xx-video.c >> index 3a7ec3b..087ccf9 100644 >> --- a/drivers/media/usb/em28xx/em28xx-video.c >> +++ b/drivers/media/usb/em28xx/em28xx-video.c >> @@ -1883,9 +1883,8 @@ static int em28xx_v4l2_open(struct file *filp) >> return -EINVAL; >> } >> >> - em28xx_videodbg("open dev=%s type=%s users=%d\n", >> - video_device_node_name(vdev), v4l2_type_names[fh_type], >> - v4l2->users); >> + em28xx_videodbg("open dev=%s type=%s\n", >> + video_device_node_name(vdev), v4l2_type_names[fh_type]); >> >> if (mutex_lock_interruptible(&dev->lock)) >> return -ERESTARTSYS; >> @@ -1898,7 +1897,9 @@ static int em28xx_v4l2_open(struct file *filp) >> return ret; >> } >> >> - if (v4l2->users == 0) { >> + if (v4l2_fh_is_singular_file(filp)) { >> + em28xx_videodbg("first opened filehandle, initializing >> device\n"); >> + >> em28xx_set_mode(dev, EM28XX_ANALOG_MODE); >> >> if (vdev->vfl_type != VFL_TYPE_RADIO) >> @@ -1909,6 +1910,8 @@ 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) { >> @@ -1918,7 +1921,6 @@ static int em28xx_v4l2_open(struct file *filp) >> >> kref_get(&dev->ref); >> kref_get(&v4l2->ref); >> - v4l2->users++; >> >> mutex_unlock(&dev->lock); >> >> @@ -2025,12 +2027,11 @@ 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->users == 1) { >> + if (v4l2_fh_is_singular_file(filp)) { >> + em28xx_videodbg("last opened filehandle, shutting down >> device\n"); >> + >> /* No sense to try to write to the device */ >> if (dev->disconnected) >> goto exit; >> @@ -2049,10 +2050,12 @@ 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: >> - v4l2->users--; >> + vb2_fop_release(filp); >> kref_put(&v4l2->ref, em28xx_free_v4l2); >> mutex_unlock(&dev->lock); >> kref_put(&dev->ref, em28xx_free_device); >> diff --git a/drivers/media/usb/em28xx/em28xx.h >> b/drivers/media/usb/em28xx/em28xx.h >> index 4360338..84ef8ef 100644 >> --- a/drivers/media/usb/em28xx/em28xx.h >> +++ b/drivers/media/usb/em28xx/em28xx.h >> @@ -524,7 +524,6 @@ 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 */ >> -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
