2011/9/17 Peter Bigot <pabi...@users.sourceforge.net>: > Thanks for providing pyusb: its support for libusb-1.0 is making my life > much easier by letting me work around the cdc_acm limitations in Linux. > > For your consideration: In my application, the Linux kernel driver for > cdc_acm will be loaded automatically when a device is inserted. I don't > want to break that, because other devices need and work with that > interface. So my script needs to detach the kernel driver. However, if > that's already been done, the underlying libusb call returns > LIBUSB_ERROR_NOT_FOUND. I want to ignore that error, but not others that > might arise in the same call. > > Under the current handling of usb.core.USBError, the numeric error code is > translated to a backend-specific error string. This makes it inconvenient > to programmatically identify the problem. > > In my case, I know I'm using libusb10, so I'd like to be able to write: > > try: > rf2500.detach_kernel_driver(0) > except usb.USBError, e: > if e.backend_errno != e.ERROR_NOT_FOUND: > raise > > The attached patch allows this. I've only provided it for the libusb10 > backend; cursory inspection suggests it's equally trivial for the others. > > Some interface choices you might want to revisit if you like this enough to > adopt it: > > * I'm not using IOError's existing errno field because the values are not > errno values, so there's a new backend_errno field. > > * I've chosen to name the backend-specific class USBError because it's > disambiguated by the module it belongs to. > > * Similarly I left the LIBUSB_ prefix off the error codes since they're > contextualized by the class. > > * I placed the error codes as class constants rather than module constants > so they're easily to hand for comparisons. If other back ends happen to > use the same name, the user code doesn't need to check which back end was > used. > > Peter >
Hi Peter, Thanks for your patch. As I will have to propagate this patch to the other backends, and I don't know when I really can do that, could you please open a ticket in Trac? -- Best Regards, Wander Lairson Costa ------------------------------------------------------------------------------ BlackBerry® DevCon Americas, Oct. 18-20, San Francisco, CA Learn about the latest advances in developing for the BlackBerry® mobile platform with sessions, labs & more. See new tools and technologies. Register for BlackBerry® DevCon today! http://p.sf.net/sfu/rim-devcon-copy1 _______________________________________________ pyusb-users mailing list pyusb-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/pyusb-users
