usb/138659: uftdi driver broken in RELENG_8/CURRENT

[Pierre-Luc Drouin]

Ed Schouten wrote:
> Hi Pierre-Luc, Hans,
>
> * Hans Petter Selasky <hselasky at c2i.net> wrote:
>   
>> You need to set raw mode for the TTY device I think. Maybe Ed can give you the 
>> function name you need to call to do that?
>>     
>
> Yes. You need cfmakeraw() to do that (or do everything yourself). See
> src/lib/libc/gen/termios.c to see what it does.
>
> So what I'm interested in, is the following:
>
> 	"even that device is answering requests slower and slower until
> 	it stalls completely within 1 hour"
>
> Could you run `pstat -t' to see what's going on when it stalls? This
> nifty tool just gives some random statistics on TTYs. Very useful to see
> what's going on. Where data is stuck, etc. etc.
>
>   
Here is what I get from pstat when I run my executable:

while ( 1 )
while? pstat -t ttyU0 | grep ttyU0
while? sleep 1
while? end
      LINE   INQ  CAN  LIN  LOW  OUTQ  USE  LOW   COL  SESS  PGID STATE
     ttyU0     0    0    0    0     0    0    0     4     0     0 ICl
     ttyU0     0    0    0    0     0    0    0     4     0     0 ICl
     ttyU0     0    0    0    0     0    0    0     4     0     0 ICl
     ttyU0     0    0    0    0     0    0    0     4     0     0 ICl
     ttyU0     0    0    0    0     0    0    0     4     0     0 ICl
     ttyU0     0    0    0    0     0    0    0     4     0     0 ICl
     ttyU0     0    0    0    0     0    0    0     4     0     0 ICl
     ttyU0     0    0    0    0     0    0    0     4     0     0 ICl
     ttyU0  1920    0    0  192  1984    0  199     4     0     0 ICOil
     ttyU0  1920    0    0  192  1984    0  199     4     0     0 ICOil
     ttyU0  1920    0    0  192  1984    0  199     4     0     0 ICOil
     ttyU0  1920    0    0  192  1984    0  199     6     0     0 ICOil
     ttyU0  1920    0    0  192  1984    0  199     6     0     0 ICOil
     ttyU0  1920    0    0  192  1984    0  199     6     0     0 ICOil
     ttyU0  1920    0    0  192  1984    0  199     6     0     0 ICOil
     ttyU0  1920    0    0  192  1984    0  199     6     0     0 ICOil
     ttyU0  1920    0    0  192  1984    0  199     6     0     0 ICOil
     ttyU0  1920    0    0  192  1984    0  199     6     0     0 ICOil
     ttyU0  1920    0    0  192  1984    0  199     6     0     0 ICOil
     ttyU0  1920    0    0  192  1984    0  199     6     0     0 ICOil
     ttyU0  1920    0    0  192  1984    0  199     6     0     0 ICOil
     ttyU0  1920    0    0  192  1984    0  199     6     0     0 ICOil
     ttyU0  1920    0    0  192  1984    0  199     6     0     0 ICOil