Re: System hangs when using USB 3.0 HD with on Ubuntu

James Bottomley
2010-04-21T14:04:54Z

On Wed, 2010-04-21 at 09:52 -0400, Mark Lord wrote:
> On 21/04/10 08:47 AM, Luben Tuikov wrote:
> >>>> starts at line 8816. (It says the
> >> command
> >>>> is a BLANK command, but it's incorrectly
> >> identified that command.)
> >
> > Application clients should send ATA PASS-THROUGH (16) and never the
> 12 byte version to ATAPI devices behind a SAT bridge, whose opcode is
> interpreted as BLANK (as pointed out by Doug), and BLANK executed.
> ..

> That's a nice self-proclamation.
> Got a pointer to a SAT or ATA/SATA standard that says it for real?

I'm afraid it's just part of the usual standards confusion. I think
what they were thinking is that no-one would use SATL with ATAPI ...
although I bet someone will ...

> The problem with that statement (above), becomes.. what to use
> for the initial IDENTIFY request, before the type of device is known?

But this isn't a userspace problem. By the time we present the device
to userspace, we already know what it is ... so you can go by device
type and only use ATA_12 for disk devices.

For kernel space, we never use the encapsulation commands anyway, we
always go by the transport.

James