HPS USB stack API change
Alfred Perlstein
alfred at freebsd.org
Thu Jun 14 23:48:37 UTC 2007
* Hans Petter Selasky <hselasky at c2i.net> [070614 02:56] wrote:
> Hi all!
>
> I'm planning to add another argument to "usbd_start_hardware()", which is a
> delay value that gives the delay in microseconds or maybe milliseconds before
> the transfer is actually queued. This can be used to reduce the polling rate
> on BULK-IN transfers among other things, to reduce the overall power usage,
> and to safely create infinite polling loops without fearing BUS overusage in
> case of failure conditions.
>
> For example:
>
> usbd_start_hardware(xfer, 200000); //200 ms delay
>
> A delay value of zero indicates no delay.
>
Sounds like a good idea.
> I plan to implement this re-using the timeout callout.
>
> Any comments ?
Can't comment as I'm not that familiar with the existing underlying
code.
--
- Alfred Perlstein
More information about the freebsd-usb
mailing list