Quoting Alan Stern <[EMAIL PROTECTED]>:

> On Fri, 14 Nov 2003, ron ta�eza wrote:
> 
> > Hi,
> > 
> > I'm using v2.4.18 (Slackware 8.1) and usb-uhci.
> 
> You should consider moving to a more recent kernel.
> 
I would like to.. but.. we'll see. It's not possible at the moment.

> > 3. I'd like to read some data from the bulk in endpoint. If I submit an URB
> 
> > with a buffer size of 2000 bytes, how much data do I get every time my
> complete 
> > function is called? I'm assuming it's every time the USB core receives a 
> > bulk "packet" (max of 64 bytes = bulk in endpoint's wMaxPacketSize), and
> NOT 
> > when the buffer has accumulated 2000 bytes.. Is this correct?
> 
> Your guess is wrong.  You will get 2000 bytes or the amount accumulated 
> when a short packet (< wMaxPacketSize) is received, whichever comes first.
> 
Thank you. It makes reading data easier.


Quoting David Brownell <[EMAIL PROTECTED]>:

> Alan Stern wrote:
> > On Fri, 14 Nov 2003, ron ta=F1eza wrote:
> >>1. I'd like to write some data to the bulk out endpoint. If wMaxPacketS=
> ize is=20
> >>64, and I'd like to write, say, 200 bytes, can I just set the urb's=20
> >>buffer_length to 200? Does the USB core automatically segment the data =
> to 64-
> >>byte chunks?
> >=20
> >=20
> > Yes.
> >=20
> >=20
> >>2. Is the same with interrupt out?
> >=20
> >=20
> > Yes.
> 
> You're thinking of 2.6 there ... on 2.4, not all HCDs support
> interrupt transfers of more than one packet (either direction).
> 
> But on 2.6, bulk and interrupt transfers should be identical
> in almost all aspects except that interrupt transfers involve
> reserved bandwidth.  Much simpler.
> 

Not all HCDS support this? Hmmm.. the problem is I'm making a driver for a 
device that I still don't have (I only have the descriptor specs). But I _will_ 
have access to the device.. in 1-2 weeks time. Does anybody know if usb-uhci on 
2.4.18 support automatic segmentation of interrupt data?

Thanks for the replies!

- Ronald


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