Date: Mon, 24 Jan 2005 11:13:26 -0800 From: Sam Leffler <sam@errno.com> To: ticso@cicely.de Cc: "Kurt J. Lidl" <lidl@pix.net> Subject: Re: ttyd0/cuad0 - why is there still this duality ? Message-ID: <41F548D6.9060409@errno.com> In-Reply-To: <20050124180840.GH628@cicely12.cicely.de> References: <20050124083043.GA8729@kukulies.org> <20050124151612.GC628@cicely12.cicely.de> <20050124124250.A27718@pix.net> <20050124180840.GH628@cicely12.cicely.de>
next in thread | previous in thread | raw e-mail | index | archive | help
Bernd Walter wrote: > On Mon, Jan 24, 2005 at 12:42:50PM -0500, Kurt J. Lidl wrote: > >>On Mon, Jan 24, 2005 at 04:16:13PM +0100, Bernd Walter wrote: >> >>>On Mon, Jan 24, 2005 at 09:30:43AM +0100, Christoph P. Kukulies wrote: >>> >>>>Just a question. Maybe it isn't true but to me it seems there >>>>is still this duality between ttyd and cuad serial devices. >>>> >>>>Why is that? I'm just asking because someone I was talking with >>>>about modems an comm programs was 'criticising' this fact >>>>in FreeBSD "while other systems long have abandoned this dualism"? >>> >>>Because modems are still used for dial-in and dial-out. >>>tty handing out to getty and cua to the dial out process. >>>Moreover this handling was recently added for usb serials under >>>-current. >>>If other systems loose features - well it's their problem. >> >>That's a very limited way of looking at the functionality. If you >>want to support the functions of both dialin and dialout on one >>serial port, there doesn't need to be more than one kernel device. >>Just because support for this got hacked into 4.2BSD in a gross >>manner doesn't mean that there isn't a better of doing this. > > > You still have the option to just ignore existenz of tty* devnodes. > > >>Having seperate dialout and dialin devices really are just a kludge >>for having the kernel doing locking that could be done in userland >>code. > > > tty* vs cua* is more than just locking. > > >>Just because FreeBSD does this the same way it's been done on >>BSD-ish systems for the last 15 years doesn't mean there isn't a >>better way of doing it. > > > Yes, but this way it just works and applications used it for many > years. > Portable modem-aware applications have never used it (speaking as someone that wrote many modem-oriented applications like tip and hylafax). I've never found a case where you cannot implement the equivalent functionality outside the kernel. Sam
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?41F548D6.9060409>