error codes for suspended printers

[Oliver Neukum]

Michael Sweet wrote:

> Oliver Neukum wrote:
>> Hi,
>> 
>> I am implementing power management for usb printers in the kernel.
>> Which error code should be returned if CUPS tries to write to a suspended
>> printer?
> 
> ENODEV would work with the current USB backend that uses the printer
> character device - that would trigger the automatic retry after a
> certain amount of time.  The kernel would need to wake the printer
> up, however.

Thank you. ENODEV it shall be.

> That said, USB backend development on Linux is moving towards the
> user-mode USB API, so you might want to look at STR #1575 and build
> on that:

Unfortunately, on the kernel side, we cannot simply drop support
for usblp and we want it to do something sensible upon suspend.

        Regards
                Oliver