Re: [Patch] Increase USBFS Bulk Transfer size

Markus Rechberger
2011-10-14T02:47:57Z

On Fri, Oct 14, 2011 at 12:19 AM, James Courtier-Dutton
<james.dutton@gmail.com> wrote:
> Why don't you try a bulk size of 12032 instead of 24064 and not try 12288 as
> you appear to be doing in the logs. Post the logs for that.

I tried that earlier already of course it fails. If I could pick a
smaller transfer size I would be happy since
the device would work with all 2.6.x kernels out of the box and I
wouldn't have to waste my time with it.
Unfortunately it requires the 24064 bytes.
The more flexible device A which is mentioned here confirms that there
can be some impact on the
bulk transfer size.
However to learn about this it's needed to look at the bottom line of
USB on the physical layer.

And I disagree with Alan Cox it's not about being a crappy device or
not, it's more like about something
that is not well understood here. Most people are familiar with
Software only here and not with the physical
USB bottom Layer, otherwise the fact that the devices can have an
impact on this wouldn't be such a surprise.

Markus