On Wednesday 18 April 2007, Tejun Heo wrote: > Mark Lord wrote: > > Chuck Ebbert wrote: > >> Mark Lord wrote: > >>> I'll patch it locally on my own machines, but what about the tens > >>> of thousands of other Seagate notebook drive owners out there? > >>> > >> > >> This is a problem with Seagate specifically, spinning back up > >> on receipt of some command after spindown? > > > > No, they just seem to be affected worse by it than some other brands. > > The bug is that libata/SCSI now spin-down the drive before the distro's > > scripts are done with it, so it spins down, and then gets spun up again > > by the distro, and then spun down again by the distro. > > > > And along the way, one/both of the two causes a full mechanism "park", > > which is hard on things if abused (like this). > > > > Or at least that's what I recall for it. Tejun? > > This really isn't a regression. It's been always like that with libata. Tejun, it is a regression over IDE subsystem (so all PATA and some SATA also). Dave/Chuck, this also seems like a FC7 regression (because of the libata PATA switch). > libata doesn't make devices go into standby mode and shutdown(8) does > it for libata. The problem here is that libata does issue > SYNCHRONIZE_CACHE on shutdown. So, the sequence of event is... > > 1. shutdown(8) issues SYNCHRONIZE_CACHE followed by STANDBY_NOW > 2. kernel shutdown starts > 3. libata shutdown issues SYNCHRONIZE_CACHE > 4. power goes off > > Some drives seem to spin up at step #3 even when its cache is clean and > power goes off right after the disk finishes the command. So, it's > really bad when it happens - spin down, spin up followed by immediate > power off. > > SCSI part of the fix is queued in scsi-misc-2.6 tree and libata-dev part > is acked and waiting to be merged, so the fix will be available in > 2.6.22. However, it's disabled by default to remain compatible with the > current behavior and requires userland change to fully fix the problem. - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
