force the last packet of a transfer to be smaller than the maximum
packet size. The only time this matters is if the transfer size is
a multiple of the maximum packet size, in which case a 0 length packet
is sent last.
Some weird devices require this behaviour to determine the end of
a transfer.
by Nick Hibma):
use NULL not 0
declare all local definitions static
rename s/usbd_request/usbd_xfer/ s/reqh/xfer/
rename s/r/err/
use implicit test for no err
KNF
the device driver instead of happening automagically in the HC driver.
This affects both the HC-USBD interface as well as the USBD-device
interface.
This change will allow DMA buffers to be reused e.g. in isochronous
traffic.
Add isochronous support to the UHCI driver (not for OHCI yet).
is unused in our USB stack.
Once upon a time, when I started writing the USB stack for NetBSD, there
was an effort to make a standard for how USB device drivers should interact
with the rest of the USB stack. This effort had contributors from just
about all Un*x camps (but not Micro$oft :). I based my design on one of their
early proposals since I thought it would be a good idea if we could all
share device drivers with a minimum effort. Shortly after I started my work
all the free Un*x people were thrown out of the USBDI work since we did not
pay the USB membership fee. Well, some time has passed now and the work of
the standardization group is almost public again. But alas, the new standard
has grown to be a monster! I do not want to have this as the basis for the
*BSD USB stack; it is far too complicated.
So, since we are not even close to being compilant with the standard, I've
thrown out some old baggage.
interrupt context.
[I had some feline debugging help here. I noticed that every time Kem,
our kitty, jumped onto the USB keyboard the machine crashed.]