On Fri, 26 May 2006, Wittawat Yamwong wrote: > On Friday 26 May 2006 21:52, Lauri Pirttiaho wrote: >> [...] >> I would propose changing the behavior of sanei_usb_read bulk >> so that in the case of NAK (resource temporarily unavailable) >> the size is returned as 0 and the return value is set >> either to SANE_STATUS_GOOD (read OK, just no data >> at this moment) or SANE_STATUS_BUSY (device can not >> respond right now). Both will work even though probably >> the latter one is more in line with the meaning of USB NAK >> in this case. > > I vote for the latter (SANE_STATUS_BUSY) so that it is possible to distinguish > between NAK and zero-length packet.
sanei already makes this distinction. zero length packet will come back as SANE_STATUS_EOF, if the return value was 0 instead of negative (which i find slightly misleading) allan -- "so don't tell us it can't be done, putting down what you don't know. money isn't our god, integrity will free our souls" - Max Cavalera
