On Thursday 29 April 2010 09:10:42 Laurent Pinchart wrote: > On Thursday 29 April 2010 08:44:29 Hans Verkuil wrote: > > > > 3) Investigate what needs to be done to replace the bkl with a v4l2-dev.c > > global mutex. Those drivers that call the bkl themselves should probably be > > converted to do proper locking, but there are only about 14 drivers that do > > this. The other 60 or so drivers should work fine if a v4l2-dev global lock > > is used. At this point the bkl is effectively removed from the v4l > > subsystem. > > > > 4) Work on the remaining 60 drivers to do proper locking and get rid of the > > v4l2-dev global lock. This is probably less work than it sounds. > > > > Since your patch moves everything down to the driver level it will actually > > make this work harder rather than easier. And it touches almost all drivers > > as well. > > Every driver will need to be carefully checked to make sure the BKL can be > replaced by a v4l2-dev global mutex. Why would it be more difficult to do so > if the BKL is pushed down to the drivers ? Note that you can completely skip the step of a v4l2-dev global mutex with Frederic's patch. This is the only use of the BKL in the common v4l2 code as far as I can tell, so instead of introducing yet another global lock, you can go straight to stage 4 and look at each driver separately, possibly introducing a per driver lock. Arnd -- 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
