Hi Markus, [ although you shouldn't overrate my opinion here I'm giving my $0.02 ] The problem with this approach are race conditions. You can't reliably use the result of this function if you don't ensure that no thread is started during / after the query. As far as I understood your idea you try to solve this issue with the allow-dvb-files-to-be-locked patch. But that patch doesn't handle file descriptors which have been opened before you did the "lock". Of course you can do additional work to fix that too - but imho the easier (and safer from a design-pov) approach is to do the locking at the bridge level as Steve did. I don't think that there are issues with handling it there - as neither dvb-core nor the frontends access the device directly (dvb-core via callbacks and the frontend via i2c adapter). Or do I miss something here? Christoph 2007/8/14, Markus Rechberger <mrechberger@xxxxxxxxx>: > Could anyone comment or add this patch? > > thanks, > Markus > > On 8/9/07, Markus Rechberger <markus.rechberger@xxxxxxx> wrote: > > Following patch adds the functionality to check if the dvb framework is > > idle or currently processing some commands. > > > > The return value of that function is true if fepriv->thread is set and > > false if not. > > > > This might become important for devices which supports video4linux > > (analogue TV) and digital TV. In case of a firmware reupload for a > > specific mode one framework has to be idle and should not interfere, > > this function adds the possibility for checking the current status of > > the DVB side. > > > > Signed-off-by: Markus Rechberger <markus.rechberger@xxxxxxx> > > > > http://mcentral.de/~mrec/patches/dvb_frontend_eventstatus.diff > > > > diff -r cae47793b091 linux/drivers/media/dvb/dvb-core/dvb_frontend.c > > --- a/linux/drivers/media/dvb/dvb-core/dvb_frontend.c Tue Aug 07 > > 10:52:55 2007 -0300 > > +++ b/linux/drivers/media/dvb/dvb-core/dvb_frontend.c Thu Aug 09 > > 13:53:47 2007 +0200 > > @@ -133,6 +133,25 @@ struct dvb_frontend_private { > > }; > > > > static void dvb_frontend_wakeup(struct dvb_frontend *fe); > > + > > +int dvb_frontend_eventstatus(struct dvb_frontend *fe) > > +{ > > + struct dvb_frontend_private *fepriv = fe->frontend_priv; > > + struct dvb_fe_events *events = &fepriv->events; > > + int ret; > > + > > + if (mutex_lock_interruptible (&events->mtx)) > > + return -EINTR; > > + > > + ret = (fepriv->thread) ? true:false; > > + mutex_unlock (&events->mtx); > > + > > + return ret; > > +} > > + > > + > > + > > +EXPORT_SYMBOL(dvb_frontend_eventstatus); > > > > static void dvb_frontend_add_event(struct dvb_frontend *fe, fe_status_t > > status) > > { > > diff -r cae47793b091 linux/drivers/media/dvb/dvb-core/dvb_frontend.h > > --- a/linux/drivers/media/dvb/dvb-core/dvb_frontend.h Tue Aug 07 > > 10:52:55 2007 -0300 > > +++ b/linux/drivers/media/dvb/dvb-core/dvb_frontend.h Thu Aug 09 > > 13:52:26 2007 +0200 > > @@ -170,6 +170,8 @@ extern void dvb_frontend_detach(struct d > > > > extern void dvb_frontend_reinitialise(struct dvb_frontend *fe); > > > > +extern int dvb_frontend_eventstatus(struct dvb_frontend *fe); > > + > > extern void dvb_frontend_sleep_until(struct timeval *waketime, u32 > > add_usec); > > extern s32 timeval_usec_diff(struct timeval lasttime, struct timeval > > curtime); > > > > > > > > > > _______________________________________________ > > linux-dvb mailing list > > linux-dvb@xxxxxxxxxxx > > http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb > > > > > -- > Markus Rechberger _______________________________________________ linux-dvb mailing list linux-dvb@xxxxxxxxxxx http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb
