Date: Wed, 25 Jun 2003 14:37:38 +0200 From: Bernd Walter <ticso@cicely12.cicely.de> To: Danny Braniss <danny@cs.huji.ac.il> Cc: ticso@cicely.de Subject: Re: USB, select/poll for ucom Message-ID: <20030625123737.GE52854@cicely12.cicely.de> In-Reply-To: <E19V9N4-000CpW-00@cs.huji.ac.il> References: <20030625120837.GC52854@cicely12.cicely.de> <E19V9N4-000CpW-00@cs.huji.ac.il>
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On Wed, Jun 25, 2003 at 03:27:30PM +0300, Danny Braniss wrote:
> > On Wed, Jun 25, 2003 at 01:13:56PM +0300, Danny Braniss wrote:
> > > hi,
> > > while trying to port an application that works with tty to uplcom/ucom,
> > > (and it doesn't work :-), and looking at the kernel sources and
> > > trying to figure out USB, i think that select(2)/poll(2) will not work,
> > > correct?
> >
> > I've seen Problemes with non 8n1 communications and I've also seen
> > problems because most USB adapters only deliver 5.5V to the lines.
> > I never noticed any select/poll problems and I don't think we have any
> > because this is handled in common code at tty level.
> >
> > If you have any condition that shows something different please let
> > us know.
> >
>
> i turned debug on and i could not see any calls to ucomread,
> the program calls select(...) - but select does not initiate anything,
> it justs waits to be woken when something is received (in the case of reading),
> now, unless im wrong - which well could be :-), the read in this case must be
> started - usb is a master/slave protocol, and this is not happening.
Because you don't talk to ucom directly - you talk to tty layer.
See src/sys/kern/tty*
> if(select(fdset,...)) {
> if(FD_ISSET(ifd, fdset))
> read(ifd, ...
> ...
> }
> danny
> PS: im using 5.1-current, and im trying to get a Towitoko smartcard reader to
> work.
Forget it - if I'm not wrong Towitoko readers use 7 bit transfers and
that's your problem.
It's doesn't with at least uplcom and uftdi - Towitoko is using PL2303
chips in their own USB product.
The only thing you can do to get this working is by fixing 7 bit
transfers.
--
B.Walter BWCT http://www.bwct.de
ticso@bwct.de info@bwct.de
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