Subject: com driver lockup on i386
To: None <>
From: Dirk Duellmann <>
List: current-users
Date: 06/13/1994 09:55:09
I am using a cheap serial board (without FIFO) to drive a modem at
19.2k baud. Board and driver worked quite well with a 21. Feb (just some
silo overflows from time to time). Since i upgraded to the 31. May
kernel the com port looks up every ~10 minutes during protocol transfer
(term/Kermit). The tty state (pstat -t) in this cases is OCBA 
which means that the driver is waiting for the next tx-ready interrupt 
(at least as far as i understand the tty/com code). Since the UART
status register shows already the tx-ready bit the driver has probably
missed the last interrupt and waits forever. 
If i check this bit in the driver and call comstart accordingly the
lockup disappears but the transfered byte still seems to be lost.
Is there a REAL fix for this problem or  somebody else working on this?

           Dirk Duellmann

Dirk Duellmann, DESY (-FH1T-), Notkestr. 85, 22603 Hamburg, Germany
phone: +49-40-8998-3461
fax:   +49-40-8994-4385
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