Citeren Charles Lepple <[email protected]>:
Several years ago on the linux-usb list, it was often pointed out that the kernel was supposed to honor the wMaxPacketSize field, and fragment the requests accordingly. While this was suggested for performance reasons (fewer round trips between user and kernel space), it should still hold true for less frequent transfers.
This was my understanding too, but for instance the blazer_usb (and megatec_usb) also fragment transfers in 8-byte chunks themselves. A while back we tried to query for larger chunks, but this wasn't reliable at all.
It looks like we can't trust that the kernel will do this for us, so I guess it would be better to do this in the libusb.c module. If memory serves, it would be possible to get wMaxPacketSize somehow from the device handle.
Best regards, Arjen -- Please keep list traffic on the list _______________________________________________ Nut-upsdev mailing list [email protected] http://lists.alioth.debian.org/mailman/listinfo/nut-upsdev
