Re: strange ucom (uplcom) error

On Tuesday 18 January 2005 13:06, Emanuel Strobl wrote:
> Dear experts,
>
> I have two USB-RS232 Adaptors, both with PL2303 chipset. One is working the
> other one not (I hate to say it but both are working under win).
>
> The not working (more expensive) one gets recognized as ucom0 and I have
> ucom0, also I can receive signal but not transmit.
>
> When I connect the (more expensive) adopter to a serial console (FreeBSD
> comconsole) I can see all kernel messages but I can't type any charecter
> when I see the login. If I change to the cheaper adopter everything is
> working fine. I compared 'stty -a -f /dev/ucom0' and both adaptors show the
> same settings.
>
> I'm using tip (ucom0:dv=/dev/ucom0:br#115200:pa=none:) on RELENG_5 (from
> this weekend)
>

Hi,
I am by no means an expert here, just couple of my observations.
I have two Prolific2303 adapters and they exhibit both some peculiarity.
I use minicom for serial communication. With my pl2303 based adapters, I must 
first start minicom, change something (toggle harware flow control as an 
example) and after that, I can use the adapter. Without this, no characters 
are seen, however, what I type is send to the other side. There is something 
incorrect in USB stack maybe, but with this workaround I can live with this. 
I have no possibility to investigate further, if someone, however, makes a 
path to be tested, I can do it.
Regards,
Milan