uplcom / ucom problems on RELENG_5

[Mike Tancsa]

At 07:49 AM 30/03/2005, Bernd Walter wrote:
>On Wed, Mar 30, 2005 at 07:22:07AM -0500, Mike Tancsa wrote:
> > At 05:41 AM 30/03/2005, Bernd Walter wrote:
> > >> putc to a clist with no reserved cblocks
> > >> putc to a clist with no reserved cblocks
> > >> putc to a clist with no reserved cblocks
> > >> putc to a clist with no reserved cblocks
> > >> putc to a clist with no reserved cblocks
> > >> putc to a clist with no reserved cblocks
> > >> putc to a clist with no reserved cblocks
> > >>
> > >> fill up the console.  At this point, ppp is totally hung, and I cannot
> > >kill
> > >> ppp
> > >
> > >You need a way to notice a connection failure.
> > >In case of modem or line failure you should see DCD loss.
> > >Does your cabling release DCD, or do you use LQR in your configuration?
> > >Have you compared the same configuration with a classical 16550 based
> > >serial?
> >
> > Hi,
> >         PPP does see the loss, the problem is that its totally wedged and
> > cant do anything else.  In the case where there is not too much data going
> > across the serial line, the connection dropping has no adverse effect.  I
> > have LCP keep alives enbled and it does detect the link going away and 
> does
> > properly redial.  However, it seems where there is too much outstanding
> > data things get into trouble.
>
>That's possible - currently we can't control the transmit/receive
>buffers inside the USB device.
>
> > What more information can I provide to help track this problem down ?
>
>We need to implement complete flushing support for uplcom.

Hi,
         Is this problem particular to the uplcom driver ?   In other 
words, if I found a serial adaptor or modem based on uftdi would I avoid 
this problem ?

Thanks,

         ---Mike