Hi Devin, > Hello Manu, > > The argument I am trying to make is that there are numerous cases > where you should not be able to use both a particular DVB and V4L > device at the same time. The implementation of such locking should be > handled by the v4l-dvb core, but the definition of the relationships > dictating which devices cannot be used in parallel is still the > responsibility of the driver. > > This way, a bridge driver can say "this DVB device cannot be used at > the same time as this V4L device" but the actual enforcement of the > locking is done in the core. For cases where the devices can be used > in parallel, the bridge driver doesn't have to do anything. I follow what you mean. Why I emphasized that it shouldn't be at the core, but basically in the bridge driver: Case 1 - there is a 1:n relation, In this case there is only 1 path and 3 users sharing that path In such a case, You can use such a mentioned scheme, where things do look okay, since it is only about locking a single path. Case 2 - there is a n:n relation, in this case there are n paths and n users In such a case, it is hard to make the core aware of all the details, since there could be more than 1 resource of the same category; Mapping each of them properly won't be easy, as for the same chip driver Resource A on Card A, would mean different for Resource A on Card B. Case 3 - there is a m:n relation, in this case, there are m paths and n users This case is even more painful than the previous ones. In cases 2 & 3, the option to handle such cases is using a configuration scheme based on the card type. I guess handling such would be quite daunting and hard to get right. I guess it would be much more efficient and useful to have such a feature to be made available in the bridge driver as it is a resource of the card configuration, rather than a common bridge resource. Manu -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
