mpr(4) and disable_eedp

[Lee Brown]

On Mon, Sep 10, 2018 at 10:51 AM, Kenneth D. Merry <ken at freebsd.org> wrote:

> On Mon, Sep 10, 2018 at 09:47:00 -0700, Lee Brown wrote:
> > On Thu, Nov 16, 2017 at 6:28 AM, Kenneth D. Merry <ken at freebsd.org>
> wrote:
> >
> > > On Wed, Nov 15, 2017 at 12:24:47 -0800, Lee Brown wrote:
> > > > I'm looking to build a SAS array with a Dell MD1420.  It will be
> attached
> > > > via a SAS 9300-414E HBA in a Dell R330.
> > >
> > > In theory it should be fine.  I haven't used a Dell enclosure
> recently, but
> > > from posts here, it seems that they like to turn on Type 2 Protection
> > > Information on the drives.  (Assuming you buy the drives from Dell.)
> > >
> > > If they do that, you can either reformat, or see the patch here for the
> > > mpr(4) driver to disable using protection information:
> > >
> > > https://docs.freebsd.org/cgi/getmsg.cgi?fetch=308820+0+
> > > archive/2017/freebsd-scsi/20171022.freebsd-scsi
> > >
> > > I have been using this patch in production on an 11.1 kernel with great
> > success.
> >
> > I'm upgrading to 11.2 today and am wondering what's required to push this
> > into the source tree (so I can be lazy next time and not have to
> patch)?  I
> > can provide testing and maybe the MD1420 could be added to the officially
> > supported hardware list?  Let me know how I could help.
> >
> > BTW, there's a typo in the patch for mpr.c "dsiable" should be "disable":
> > +    OID_AUTO, "dsiable_eedp", CTLFLAG_RD, &sc->disable_eedp, 0,
>
> I put in a slightly different version of the change in March 2018 that just
> disables Type 2 data protection:
>
> https://svnweb.freebsd.org/base?view=revision&revision=331422
>
> I MFCed it a few days later, so 11.2 should work without a patch.  If it
> doesn't, let me know.  There is no sysctl/tunable variable in the new
> version.
>
> Many Thanks Ken.

I'm in the middle of building the two releases, so I'll stop now and
restart with a fresh checkout.
If there are problems I'll be back, but I probably won't be able to test
this until tomorrow evening.

--lee