Date: Thu, 18 Jun 1998 22:14:25 -0600 (MDT) From: "Kenneth D. Merry" <ken@plutotech.com> To: jonny@jonny.eng.br (Joao Carlos Mendes Luis) Cc: ken@plutotech.com, jonny@jonny.eng.br, ckempf@enigami.com, freebsd-scsi@FreeBSD.ORG Subject: Re: Rolling CAM in, what is still needed? Message-ID: <199806190414.WAA10410@panzer.plutotech.com> In-Reply-To: <199806190400.BAA25325@roma.coe.ufrj.br> from Joao Carlos Mendes Luis at "Jun 19, 98 01:00:54 am"
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Joao Carlos Mendes Luis wrote... > #define quoting(Kenneth D. Merry) > // I know that changes in API can be a PITA, I had to port a very > // large application from the old scsireq/SCIOCCOMMAND system to the new > // passthrough driver. We can't keep old API's around forever for no > // particular reason, so I'd rather go ahead and port things. > > Sorry for my ignorance, but is this interface FreeBSD only ? Nope, it's also used in NetBSD and OpenBSD, I think. > If it's somewhat generic (say, *BSD), I'd prefer to have both, > and have immediate portability for "future" applications. > Is there a big advantage on the new scheme ? Yeah, it doesn't involve needless translation, and you can send more than just SCSI commands with it. You can send any type of CCB using the standard passthrough ioctl. > At least, while CAM is in transition mode, being available only > as patches, the compatibilty API would make easy to choose cam > or not-cam during boot time (for those interfaces available in > both modes, of course). I hope that's what you said above. Yeah, you could do it that way I suppose. But there's more than just random SCSI utilities that will break if you run a CAM userland with a regular -current kernel. The device statistics code is completely different in CAM, and all the dk* stuff doesn't exist anymore. i.e. systat, iostat, vmstat and rpc.rstatd compiled under CAM won't work right with a regular -current kernel, and vice versa. > As always, JMHO, and not being an involved programmer, my vote > is not much here. :) I'm not terribly inclined to do it myself, at the moment I don't think it's really worth the effort. If someone else thinks it's important to have scsireq support, and wants to go through the trouble to do it, I may be able to fish out my (probably now broken) code to implement the SCIOCCOMMAND in the passthrough driver. You'll still have to point the applications to /dev/rpassn, though. Ken -- Kenneth Merry ken@plutotech.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message
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