HEADSUP usb2 (usb4bsd) to become default in 2 weeks.

Hans Petter Selasky hselasky at c2i.net
Tue Dec 23 16:34:14 UTC 2008


Hi,

On Tuesday 23 December 2008, Dag-Erling Smørgrav wrote:
> Alfred Perlstein <alfred at freebsd.org> writes:
> > Dag-Erling Smørgrav <des at des.no> writes:
> > > You know very well that there are, and you also know very well that
> > > this is too big a change to go in without discussion.
> >
> > Perhaps you can list them for me [...]
>
> There are serious issues with the permissions model, which were raised
> in Strasbourg and AFAIK never addressed.

This is more complicated than you think. If you require a change in this area 
than please point me to an existing example implementing something similar. I 
know about the "kern_priv()" function, but there are no specific groups for 
USB, which needs to be discussed. The current implementation is good enough 
for most use cases in my opinion.

> There are complaints from other developers (Warner, for one) that their
> reviews were ignored.
>
> > 3) I think you were mad about whitespace or something, but like this
> >    case, you were not up for bringing specifics to the table.
>

It is limited what one person can do.

> That's untrue - I dropped the issue because I thought thompsa@ was
> working on it, but he didn't touch the userland parts.  I have a
> 3,000-line diff for libusb20 which no longer applies due to intervening
> changes.  Looking at the updated code, I'm still concerned about the
> widespread use of obufscated pointer arithmetic - the LIBUSB20_ADD_BYTES
> macro, for instance, is even worse now than when I last looked at
> libusb20.

If you have a better way to do things then please show me. If you think it 
still applies then please sent it to me.

LIBUSB20_ADD_BYTES() is a hack to circumvent things like un-constifying and 
making a byte increment to any pointer type. USB descriptors are byte-packed. 
I have tested the macro with several kinds of compilers and none have 
complained yet.

--HPS


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