On Sat, 16 Oct 2010 10:44:56 -0300 Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxx> wrote: > drivers/media/video/via-camera.c: In function ‘viacam_open’: > drivers/media/video/via-camera.c:651: error: too few arguments to function ‘videobuf_queue_sg_init’ > The fix for this one is trivial: > drivers/media/video/via-camera.c:651: error: too few arguments to function ‘videobuf_queue_sg_init’ > > Just add an extra NULL parameter to the function. So I'm looking into this stuff. The extra NULL parameter is a struct mutex, which seems to be used in one place in videobuf_waiton(): is_ext_locked = q->ext_lock && mutex_is_locked(q->ext_lock); /* Release vdev lock to prevent this wait from blocking outside access to the device. */ if (is_ext_locked) mutex_unlock(q->ext_lock); I'd be most curious to know what the reasoning behind this code is; to my uneducated eye, it looks like a real hack. How does this function know who locked ext_lock? Can it really just unlock it safely? It seems to me that this is a sign of locking issues which should really be dealt with elsewhere, but, as I said, I'm uneducated, and the changelogs don't help me much. Can somebody educate me? Thanks, jon -- 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
