On Wed 6 March 2013 10:48:13 volokh84@xxxxxxxxx wrote: > Hi, > Hans > > I found in d8077d2df184f3ef63ed9ff4579d41ca64e12855 commit, > that V4L2_CTRL_FLAG_VOLATILE flag was disabled for some STD controls > and fully disabled g_ctrl iface. So How can userspace know about changing some values? VOLATILE is used when register values can change automatically (e.g. if autogain is on and the device regulates the gain and updates that gain register itself). However, testing proved that the hardware doesn't update anything when in autogain mode, hence volatile support isn't needed. Note that the control framework always caches the last control value, so to get non-volatile controls the framework just returns that cached value. Regards, Hans -- 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
