tty driver strange problem

Tom Reingold tr at samadams.princeton.edu
Thu Mar 1 13:40:16 AEST 1990


In article <1383 at cirrusl.UUCP> saeed at sunseeker (Saeed Talebbeik) writes:
$ I am writing a tty driver for a multiport intelligent serial card under SCO
$ XENIX SYSTE. My test case for transmit is very simple. I try to "cat" a file
$ of 1 Mb size and redirect the output to the 8 ports at the same time in the
$ background "cat filename > /dev/port[1-8] &". The problem is an elusive bug.
$ Every now and then the processes go to sleep on some channel and the whole
$ test freezes up. I have increased the number of system clists from 100 to 1000.
$ That did not solve the problem either. The xon/xoff handshaking is done automatically by the board and the driver does not have to handle that. Does anybody 
$ know any debugging hints to trace the problem. I would like to know if I can
$ find out what those channel numbers which te processes are sleeping mean? 
$ Does this look like a driver or a hardware problem ? Any comments or help
$ is very appreciated.     Thanks.

Well, gee you may have a hardware problem or a driver problem, but
first, your command syntax is wrong!  You can't send your output to
more than one file using the redirection character '>'.  That's for
sending to one file only.  Check out the "tee" command.  You'll need to
invoke seven copies of this to send to eight files (give or take one
(I'm not going to check for a fencepost error in this posting)).
--
tr at samadams.princeton.edu



More information about the Comp.unix.wizards mailing list