Em Tue, 02 Sep 2014 02:58:50 +0300
Antti Palosaari <crope@xxxxxx> escreveu:
> Moikka Changbing and thanks to working that.
>
> I reviewed the first patch and tested all these patches. It does not
> deadlock USB device anymore because of patch #1 so it is improvement.
> However, what I expect that patch, it should force device unregister but
> when I use tzap and unplug running device, it does not stop tzap, but
> continues zapping until app is killed using ctrl-c.
> I used same(?) WinTV Aero for my tests.
...
> Is there any change to close all those /dev file handles when device
> disappears?
Well, we may start returning -ENODEV when such event happens.
At the frontend, we could use fe->exit = DVB_FE_DEVICE_REMOVED to
signalize it. I don't think that the demod frontend has something
similar.
Yet, it should be up to the userspace application to properly handle
the error codes and close the devices on fatal non-recovery errors like
ENODEV.
So, what we can do, at Kernel level, is to always return -ENODEV when
the device is known to be removed, and double check libdvbv5 if it
handles such error properly.
Regards,
Mauro
>
> regards
> Antti
>
>
> On 08/21/2014 05:05 AM, Changbing Xiong wrote:
> > when usb-type tuner is pulled out, user applications did not close device's FD,
> > and go on polling the device, we should return POLLERR directly.
> >
> > Signed-off-by: Changbing Xiong <cb.xiong@xxxxxxxxxxx>
> > ---
> > drivers/media/dvb-core/dmxdev.c | 6 +++++-
> > 1 file changed, 5 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/media/dvb-core/dmxdev.c b/drivers/media/dvb-core/dmxdev.c
> > index 7a5c070..42b5e70 100755
> > --- a/drivers/media/dvb-core/dmxdev.c
> > +++ b/drivers/media/dvb-core/dmxdev.c
> > @@ -1085,9 +1085,10 @@ static long dvb_demux_ioctl(struct file *file, unsigned int cmd,
> > static unsigned int dvb_demux_poll(struct file *file, poll_table *wait)
> > {
> > struct dmxdev_filter *dmxdevfilter = file->private_data;
> > + struct dmxdev *dmxdev = dmxdevfilter->dev;
> > unsigned int mask = 0;
> >
> > - if (!dmxdevfilter)
> > + if ((!dmxdevfilter) || (dmxdev->exit))
> > return POLLERR;
> >
> > poll_wait(file, &dmxdevfilter->buffer.queue, wait);
> > @@ -1181,6 +1182,9 @@ static unsigned int dvb_dvr_poll(struct file *file, poll_table *wait)
> >
> > dprintk("function : %s\n", __func__);
> >
> > + if (dmxdev->exit)
> > + return POLLERR;
> > +
> > poll_wait(file, &dmxdev->dvr_buffer.queue, wait);
> >
> > if ((file->f_flags & O_ACCMODE) == O_RDONLY) {
> > --
> > 1.7.9.5
> >
>
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