Hi, On 2006-04-17 09:07, Tamkang wrote: > Does anyone know why the position of usb_set_interface before > usb_claim_interface, get return -1 ?
As far as I know there is no libusb function called "usb_set_interface". If you refer to usb_set_altinterface, you really must claim the interface before. Using an alternative interface is just a different way of using the same interface so it is blocked by the access. > because I am trying to > developing driver sm3880 for sane-backend, and I got this I/O > Device Error, but I got fixed after, I reverse the > usb_claim_interface is on behind, after usb_set_interface function > got return 0, any one know why? I highly recommend to use the SANEI wrapper functions in sanei/sanei_usb.c for SANE backends instead of using libusb directly. At least with normal USB devices this makes life a little bit easier for you (and us, because it reduces porting issues). So you write a backend for the Microtek Scanmaker 3880? This scanner is not yet in our list. Could you give more details, e.g. the output of "sane-find-scanner -v -v" and if the scanner uses the same chipset as the 3800 or some other scanner. Bye, Henning
