Date: Tue, 6 Jul 1999 23:36:12 -0600 (MDT) From: "Kenneth D. Merry" <ken@plutotech.com> To: ohashi@mickey.ai.kyutech.ac.jp (Takeshi OHASHI) Cc: ken@plutotech.com, garbanzo@hooked.net, dmiller@search.sparks.net, akiyama@kme.mei.co.jp, freebsd-hackers@FreeBSD.ORG Subject: Re: DVD-ram Message-ID: <199907070536.XAA88983@panzer.kdm.org> In-Reply-To: <199907070458.NAA01916@atohasi.mickey.ai.kyutech.ac.jp> from Takeshi OHASHI at "Jul 7, 1999 01:58:07 pm"
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Takeshi OHASHI wrote... > Thanks for many suggestions. > > I'll try latest CAM system. Cool, I'm interested to hear how it works for you. If things don't work properly, we'll try to fix the bugs. > ken>>Can you make source code to the OD driver available, so I can take a look > ken>>at it, and see what sorts of things you have to do to make these drives > ken>>work? > > I am a beta tester of the new od driver. It almost works fine on some > beta testers system, but we cannot redistribute without Mr. Akiyama's > permit. Of course. Well, if he doesn't mind, I'd like to take a look at it at some point. > I have a new question. If od driver is needless, why cd and da drivers > are sepalate yet? Only difference is TOC ioctls, isn't it? There are more differences than just that, actually. The da driver has a dump routine and code to deal with ordered tags (no CDROM drive that I've seen can do tagged queueing, and it really only matters on write in this case). The CD driver has a builtin changer scheduler, to deal with LUN-based changers, like the Nakamichi and Pioneer boxes. (5-7 CDs, one laser, and each CD appears as a separate LUN) Because of all the audio (start, stop, play, eject, etc), TOC, and other ioctls and the changer scheduling code, the CD driver is twice as large as the DA driver. It's true that the read/write interfaces of the two drivers are very similar, but there are a number of other differences. They probably could be combined with some difficulty, but then there are booting concerns (if everything is a DA device, how can you make sure you aren't booting off a CDROM drive?), major numbers, and device names to think about as well. Ken -- Kenneth Merry ken@plutotech.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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