On Wed, 5 Mar 2014, Dan Williams wrote: > On Mon, Mar 3, 2014 at 1:25 PM, Daniel Mack <zonque@xxxxxxxxx> wrote: > > From: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> > > > > Evidently some wacky USB-ATA bridges don't recognize the SYNCHRONIZE > > CACHE command, as shown in this email thread: > > > > http://marc.info/?t=138978356200002&r=1&w=2 > > > > The fact that we can't tell them to drain their caches shouldn't > > prevent the system from going into suspend. Therefore sd_sync_cache() > > shouldn't return an error if the device replies with an Invalid > > Command ASC. > > > > Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> > > Reported-by: Sven Neumann <s.neumann@xxxxxxxxxxxx> > > Tested-by: Daniel Mack <zonque@xxxxxxxxx> > > CC: Oliver Neukum <oliver@xxxxxxxxxx> > > CC: <stable@xxxxxxxxxxxxxxx> > > --- > > Hi, > > > > this patch has been around for awhile, but hasn't gained much > > attraction, and hasn't been merged anywhere yet. Which is sad, > > as it fixes a bug on real hardware when going to suspend :) > > > > Could anyone from the SCSI people have a quick look maybe? > > Acked-by: Dan Williams <dan.j.williams@xxxxxxxxx> > > But I agree with Tejun [1], that this likely does not go far enough. > We should also be looking to fail future writes to the device or > disabling the cache. > > Tejun's comment: > "Ooh, yeah, flush failure is special. That said, I think the right way > to deal with that is marking the device as failed and fail writes / > flushes afterwards instead of failing suspend. It's hightly unlikely > the device is in any useable state after failing flushes anyway and > failing suspend has potential to lead to pretty dramatic failure > conditions (device overheating in the bag would be a common one) too." I disagree with part of Tejun's comment. In the case of the bug report leading to this patch, it is _not_ true that the device ends up in an unusable state (as far as I know). There's no reason to mark the device as failed. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
