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Date: Thu, 14 Jun 2007 16:16:45 -0700
From: Alfred Perlstein <alfred@freebsd.org>
To: Hans Petter Selasky <hselasky@c2i.net>
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Cc: freebsd-usb@freebsd.org
Subject: Re: HPS USB stack API change
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* Hans Petter Selasky <hselasky@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