Re: 82571EB: Detected Hardware Unit Hang

From: Henrique de Moraes Holschuh
Date: Mon Jul 16 2012 - 12:08:07 EST

On Mon, 16 Jul 2012, Ben Hutchings wrote:
> On Sun, 2012-07-15 at 10:35 -0300, Henrique de Moraes Holschuh wrote:
> > On Sun, 15 Jul 2012, Dave, Tushar N wrote:
> > > Somehow setting max payload to 256 from BIOS does not set this value for all devices. I believe this is a BIOS bug.
> >
> > And preferably, Linux should complain about it. Since we know it is going
> > to cause problems, and since we know it does happen, we should be raising a
> > ruckus about it in the kernel log (and probably fixing it to min(path) while
> > at it)...
> >
> > Is this something that should be raised as a feature request with the
> > PCI/PCIe subsystem?
> The feature is there, but we ended up with:
> commit 5f39e6705faade2e89d119958a8c51b9b6e2c53c
> Author: Jon Mason <mason@xxxxxxxx>
> Date: Mon Oct 3 09:50:20 2011 -0500
> PCI: Disable MPS configuration by default
> But you are welcome to share use of the fixup_mpss_256() quirk.

Meh. I'd be happy with a warning if MPSS decreases when walking up to
the tree root... i.e. a warning if any child has a MPSS larger than the

"One disk to rule them all, One disk to find them. One disk to bring
them all and in the darkness grind them. In the Land of Redmond
where the shadows lie." -- The Silicon Valley Tarot
Henrique Holschuh
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