On Tue, 15 Dec 2015, Oliver Neukum wrote: > On Thu, 2015-12-03 at 13:36 -0500, Alan Stern wrote: > > This is an old problem, but it was never resolved and it still affects > > people (Bugzilla #89511). In short, there are USB-(S)ATA bridges that > > claim to be write-back but don't support the SYNCHRONIZE CACHE > > command. > > This causes errors when filesystems try to flush data out to the disk. > > OK, maybe this is a stupid idea, but could we test the command as we > enumerate the slave and store the result? Maybe, although doing so within usb-storage would be kind of difficult -- that driver is set up to forward requests from the SCSI layer, not to generate requests of its own. Besides, usb-storage doesn't know anything about write-back vs. write-through; only sd does. I suppose sd could perform that test. 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
