On Tuesday 31 January 2006 02:00, Nate Lawson wrote: > Florent Thoumie wrote: > > On Tuesday 31 January 2006 01:24, Nate Lawson wrote: > >>I'm not concerned about the revision. I'm concerned about the vendor > >>(Generic*) and device name (STORAGE DEVICE*). Why are the *'s needed? > > > > Seemed common practice reading the other entries. > > No, that's definitely not it. In fact, the most recent entries should > be audited to see if they really need the *'s. This wildcard might > overly match the wrong devices. > > >>(Again, a PR would help track this kind of conversation as shown in > >>previous PRs about quirks. Submitters often match way too much.) > >> > >>>Do you want me to create a PR just for tracking purposes? > >>>[1] http://docs.freebsd.org/cgi/mid.cgi?20060116193024.GA95183 > >> > >>That would be nice, especially since some of the requested info is > >>missing (dmesg, usbdevs -v). However, if you cited a email in the > >>commit msg (maybe SMTP Message-ID) such that we could find it in the > >>future, that would probably be enough. I'm not trying to create a > >>bureaucracy, just make sure we don't lose information like we used to on > >>why a quirk was added in the first place. > > > > I only mentioned the freebsd-usb mailing list. I'll contact Anders to get > > additional details and I (or he) will fill a PR so that we can add it to > > the comment. > > Thanks. > > > It seems a lot of devices are concerned by the sync cache problem, would > > it be harmful to just remove this part of the code or could there be a > > way to detect if the device supports it or not? > > Well, it's important to run SYNC_CACHE in shutdown or possibly when > unmounting a filesystem. Otherwise, data could be lost on boot. > However, I support adding a USB-specific mechanism that says SYNC_CACHE > should only be run on shutdown or device_eject, that way devices that > hang after this command is run would still work at runtime. And SCSI > devices that support multiple calls to SYNC_CACHE (i.e. most non-USB > devs) would still work too. > > However, the first step is to investigate what windows and Linux do.
Linux only sends the SYNCHRONIZE_CACHE command if the WCE (Write Cache Enable) bit of the disk is set. I can't seem to find something equivalent to this in our CAM framework. I have no particular SCSI knowledge but I guess I can have a look at this tomorrow. I'm forwarding this to freebsd-scsi@ (keep me CC'ed, as I'm not subscribed to this list, yet). -- Florent Thoumie [EMAIL PROTECTED] FreeBSD Committer
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