Markus Rechberger wrote: > On 8/14/07, Christoph Pfister <christophpfister@xxxxxxxxx> wrote: >> 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? >> > > There's some other code for checking if the filehandles are open but I > don't need that patch to go into the framework, it will be stored in > the local driver. > For now my aim is to bring in the most needed patches in and nothing else. > > Markus Markus, You seem to be avoiding the issue. Christoph is trying to explain to you the same idea that I have tried to explain to you in the past -- locking of the device for use between analog and digital should take place at the bridge driver level. This is what Steve Toth has done for the :8802 port in the cx88 driver, by only allowing cx88-blackbird -or- cx88-dvb to use the hardware at any given moment. Since it is the bridge hardware that determines whether or not the device is a combo device (both analog and digital can be used concurrently) or a hybrid device (only analog or digital can be used, one at a time), and it is the bridge hardware itself, that has the limitation. the locking is only appropriate at the level of the bridge driver itself. Regards, Michael Krufky _______________________________________________ linux-dvb mailing list linux-dvb@xxxxxxxxxxx http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb
