Date: Mon, 23 Nov 1998 06:10:41 -0700 From: "Justin T. Gibbs" <gibbs@plutotech.com> To: Joel Ray Holveck <joelh@gnu.org> Cc: "Justin T. Gibbs" <gibbs@plutotech.com>, current@FreeBSD.ORG Subject: Re: 3.0-RELEASE Feedback Message-ID: <199811231318.GAA25029@pluto.plutotech.com> In-Reply-To: Your message of "23 Nov 1998 01:11:12 CST." <864srq6fzj.fsf@detlev.UUCP>
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>>> I'm considering making a change so that cd's are not probed for size. >> Why. It's one of the ways the system ensures it can successfully talk >> to the device. > >To keep a slightly more orderly startup. Rather than have a CD-ROM >dump a "Not Ready" error code to the login prompt, and miss all >mention of said CD drive in dmesg.boot, I for one would rather use a >different method. You'll get the same behavior for disk drives that the system needed to spin up, or any other type of device that requires more initialization. Again, this is a feature. If you are really concerned about the contents of your dmesg.boot, add a call to 'camcontrol' in /etc/rc that dumps the device list into dmesg.boot. >If I'm reading right, we've already sent the CD-ROM >a Test Unit Ready, two Inquiries, and a Mode Sense before sending a >read capacity command. We won't send a mode sense unless the drive can do tagged queuing. You also miss that the probe code doesn't even know that a cdrom peripheral driver exists at the point that it performs these actions. The peripheral driver can only assume that the probe took the steps necessary to identify the device, nothing more. >Are there likely to be CD-ROM failures in >which these others all succeed but the Read Capacity fails with a >sense code other than Medium Not Present or Logical Unit Not Ready >(both of which are considered successful probes by the CD probe code)? Certainly. A read capacity is the only thing in the initialization sequence that tests the mechanical ability of the device. If there is a problem with the spindle motor or laser mount, it will likely be reported in response to the read capacity. -- Justin To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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