Re: [PATCH] unbreak all modern Seagate ATA pass-through for SMART

Rene Rebe
2021-04-25T15:03:03Z

Alan Stern <stern@rowland.harvard.edu> wrote:

> On Sun, Apr 25, 2021 at 02:15:36PM +0200, Rene Rebe wrote:
> > From: Greg KH <gregkh@linuxfoundation.org>
> > Subject: Re: [PATCH] unbreak all modern Seagate ATA pass-through for SMART
> > Date: Sun, 25 Apr 2021 14:00:26 +0200
> >
> > > > I would expect that more modern devices to work. Vendors usually
> > > > linearly allocate their product ids for new devices, and we could
> > > > allow list product ids higher than this Seven to unbreak more modern
> > > > devices by default and limit the amount of device quirks needed?
> > >
> > > Vendors do not allocate device ids that way at all, as there is no
> > > requirement to do so. I know of many vendors that seemingly use random
> > > values from their product id space, so there is no guarantee that this
> > > will work, sorry.
> >
> > I did not say it is a requirement, just that they usually do speaking
> > of just this Seagate case. What is wrong with using that to
> > potentially significantly cut down the quirk list?
>
> You didn't read commit 92335ad9e895, did you? It lists a large number
> of Seagate devices that don't work with ATA pass-through, and three of
> them have product IDs that are larger than 0xab03.
>
> Please check the facts before guessing about things that will cause
> problems for other people.

I really don't appreciate the unfriendly tone on the linux kernel
mailing lists (which is why for 20 years I never felt like contributing
here mo), and well so far this change has caused a problem for me.
While I did not read that commit I was speaking from my experience
with USB devices and drivers, like the hundreds of Avision scanenrs my
SANE backend support and Canon, Fujitsu and Panasonic et
al. scanners. While you proof the point that proposed condition would
avoid 6 out of the 9 entires.

> > > What is wrong with just allowing specific devices that you have tested
> > > will work, to the list instead? That's the safest way to handle this.
> >
> > The problem is that out of the box it does not work for users, and
> > normal users do not dive into the kernel code to find out and simply
> > think their devices sucks. Even I for years thought the drive sucks,
> > before I took a closer look. If you long term want more new devices in
> > an allow list than the previous quirk list included (9 or 10 does not
> > sound that many to me), ... whatever you prefer ,-) I would rather
> > have 10 quirk disable list than potential many more white listed the
> > next years to come. Maybe we shoudl simply restore the prevoius
> > quirks.
>
> That's a possibility, and in the future we may do it. But probably not
> until the enable list grows to a comparable length.

Yeah, why future proof it now, ... which is exactly what brought us
here from the original regression. The enable list will likely not
grow quickly as most users will just expect a broken device hw/
firmware and not bother looking into it and instead live w/o SMART.

But of course I do rewrite this as requested.

René

--
René Rebe, ExactCODE GmbH, Lietzenburger Str. 42, DE-10789 Berlin
https://exactcode.com | https://t2sde.org | https://rene.rebe.de