Bill Sommerfeld wrote: > The whole "scanner as removable media" thing was a total distraction/red > herring. > > Project team (or Darren?): is there a portable way with libsane to reset > a scanner to its power-on-default or factory-default configuration? Or > does this require scanner-model-specific knowledge? > The reset-to-default behavior depends on the hardware's capability. Some scanners support reset operation. Upon device close/open, a reset command will be sent to the device. For those that don't support hardware reset, the backend will call its own init_options() or similar function to set default parameters for a device upon sane_init(), sane_open() or sane_start()[1], then write such parameters to device to acquire data. Some backend may even use all the methods to set initial state of a scanner. Application can change the parameter values by calling sane_control_option(). So, whenever a user starts to acquire image data from a scanner, the scanner's state is reset.
Thanks, Lei Chen [1] http://www.sane-project.org/html/doc013.html > I think the pragmatic answer is to not make claims about device > allocation as part of the spec for this case. > > Perhaps we could use some future project to extend device allocation to > cope with devices accessed through libusb/ugen and similar frameworks > rather than kernel drivers with device-class-specific drivers, and > another one to unify the logindevperm mechanism with device allocation. > > Neither of those seems to be this case. > > - Bill > > > > > > > >
