Date: Mon, 30 Jan 2006 21:23:06 -0800 From: Nate Lawson <nate@root.org> To: Florent Thoumie <flz@xbsd.org> Cc: freebsd-scsi@freebsd.org Subject: Re: cvs commit: src/sys/cam/scsi scsi_da.c src/sys/dev/usb umass.c usbdevs Message-ID: <43DEF43A.6090804@root.org> In-Reply-To: <200601310251.16946.flz@xbsd.org> References: <20060130202806.DCC7916A4CA@hub.freebsd.org> <200601310133.34152.flz@xbsd.org> <43DEB6C5.8090504@root.org> <200601310251.16946.flz@xbsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
Florent Thoumie wrote: > On Tuesday 31 January 2006 02:00, Nate Lawson wrote: > >>Florent Thoumie wrote: >>>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). Hmm, is WCE part of the inquiry response? [moving to scsi@ list] -- Nate
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?43DEF43A.6090804>