Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 27 Jun 1997 22:32:51 +1000
From:      Bruce Evans <bde@zeta.org.au>
To:        bde@zeta.org.au, mcgovern@spoon.beta.com
Cc:        hackers@freebsd.org
Subject:   Re: XON/XOFF intrusion
Message-ID:  <199706271232.WAA25388@godzilla.zeta.org.au>

next in thread | raw e-mail | index | archive | help
>However, I did note one interesting thing in tty.c (/usr/src/sys/kern), 
>starting on line 318 (version 2.2.1). Its the if statement that decides
>if ttyblock() gets called. I did some reduction of the expression,
>and got (in pseudo-code):
>
>if ( (tp clists > 512) && (!ICANON || tp->t_canq.c_cc != 0) && 
>	(CRTS_IFLOW || IXOFF) && !TS_BLOCK)
>
>I'd buy most of that as being reasonable, except the CRTS_IFLOW portion. Why
>would I want to introduce Xon/Xoff handling if I have CRTS_FLOW? Especially
>when this flag represents half of hardware flow control? I think it should

This is so that ttyblock() gets called to handle all types of flow control.

Bruce



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199706271232.WAA25388>