Am Donnerstag, 16. Januar 2003 01:30 schrieb David Brownell:
> Oliver Neukum wrote:
> > usb_alloc_urb (int i, int mem_flags) ->
> > usb_alloc_urb (struct usb_device *dev, int i, int mem_flags)
> >
> > Explanation:
> > The HCDs allocate and deallocate data structures during every submission.
>
> This change doesn't get away from that though ... there are two
> classes of allocation, it only helps the easy one go away:
>
> - "hcpriv" ... I posted a patch ages ago that just stores this
> in the urb, like skbuf->cb[] for network drivers.
Interesting. IMHO worth inclusion.
> - 1..N TDs ... dependant on the specific buffer passed later,
> except (usually) for ISO (where i == n)
>
> The allocation it could get rid of is "hcpriv", and there's a
> simpler way to to get rid of that (urb->cb or whatever) that
> doesn't change the usbcore API.
What prevents you from allocating a reasonable number in the general case
and as many as you may need in the iso case?
It's a case of memory vs. speed and should be benchmarked, probably.
Regards
Oliver
-------------------------------------------------------
This SF.NET email is sponsored by: A Thawte Code Signing Certificate
is essential in establishing user confidence by providing assurance of
authenticity and code integrity. Download our Free Code Signing guide:
http://ads.sourceforge.net/cgi-bin/redirect.pl?thaw0028en
_______________________________________________
[EMAIL PROTECTED]
To unsubscribe, use the last form field at:
https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
