From owner-freebsd-hardware Sat Feb 12 9:13:59 2000 Delivered-To: freebsd-hardware@freebsd.org Received: from mailman.zeta.org.au (mailman.zeta.org.au [203.26.10.16]) by builder.freebsd.org (Postfix) with ESMTP id 55E013F45; Sat, 12 Feb 2000 09:13:46 -0800 (PST) Received: from bde.zeta.org.au (bde.zeta.org.au [203.2.228.102]) by mailman.zeta.org.au (8.8.7/8.8.7) with ESMTP id EAA09932; Sun, 13 Feb 2000 04:16:21 +1100 Date: Sun, 13 Feb 2000 04:13:19 +1100 (EST) From: Bruce Evans X-Sender: bde@alphplex.bde.org To: "Jose M. Alcaide" Cc: freebsd-hardware@FreeBSD.ORG, freebsd-mobile@FreeBSD.ORG Subject: Re: [fix and RFC] interrupt-level buffer overflows with Xircom PCMCIA modem In-Reply-To: <38A56AD6.8C3E1A97@we.lc.ehu.es> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hardware@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Sat, 12 Feb 2000, Jose M. Alcaide wrote: > Now, the conclusions: perhaps RS_IBUFSIZE=256 is too low for some devices > (notably internal modems); it's only a theory. Or perhaps some devices Too large for devices with broken 16550 emulation. > have problems with RTS/CTS flow control. In any case, I suggest RTS emulation is probably also broken for there to be a problem. Ideally, the sender should check its version of RTS (i.e., CTS) before sending each character. For bug for bug compatibility with 16550 senders, the sender only needs to check it every 16th character. > the addition of a new kernel configuration option for permitting > to change RS_IBUFSIZE to any desired value. RS_IBUFSIZE doesn't exist in -current. Instead, the buffer is sized to hold 4 ticks (4.0 / hz seconds) worth of input at the current input speed (or 128 bytes if that is larger). Bruce To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hardware" in the body of the message