Re: [usb-storage] Re: 3.16 commit 89fb4cd errors on drives without SYNC CACHE

Alan Stern
2014-11-21T15:08:03Z

On Fri, 21 Nov 2014, Christoph Hellwig wrote:

> > usb-storage sets wce_default_on only for devices that are marked with
> > the US_FL_WRITE_CACHE quirk flag. Currently only two devices have that
> > flag: the Seagate Portable HDD (vendor ID 0x0bc2, product ID 0x2300)
> > and the Western Digital My Password HDD (vendor ID 0x1058, product ID
> > 0x070a).
>
> So Jeff has a drive that on its own claims WCE=1 but doesn't support
> SYNCHRONIZE_CACHE(10). I'm not sure what to do about it as it sounds
> inherently dangerous.

Maybe we should log a one-time warning when this happens and turn off
sdkp->WCE. There's not much else we _can_ do about it.

Alan Stern