Re: [PATCH 4.2.y-ckt 009/211] xhci: don't finish a TD if we get a short transfer event mid TD

From: Ben Hutchings
Date: Wed Jan 06 2016 - 21:52:16 EST


On Wed, 2016-01-06 at 11:55 -0800, Kamal Mostafa wrote:
> On Wed, 2016-01-06 at 17:05 +0000, Ben Hutchings wrote:
> > On Tue, 2016-01-05 at 11:41 -0800, Kamal Mostafa wrote:
> > > 4.2.8-ckt1 -stable review patch.ÂÂIf anyone has any objections, please let me know.
> > >
> > > ------------------
> > >
> > > From: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
> > >
> > > commit e210c422b6fdd2dc123bedc588f399aefd8bf9de upstream.
> > >
> > > If the difference is big enough between the bytes asked and received
> > > in a bulk transfer we can get a short transfer event pointing to a TRB in
> > > the middle of the TD. We don't want to handle the TD yet as we will anyway
> > > receive a new event for the last TRB in the TD.
> > >
> > > Hold off from finishing the TD and removing it from the list until we
> > > receive an event for the last TRB in the TD
> > >
> > > Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
> > > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > > [ kamal: backport to 4.2-stable: context ]
> > > Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
> > [...]
> >
> > This causes regressions (see https://bugs.debian.org/808602 and
> > https://bugs.debian.org/808953 ) so please hold off until there's a
> > complete fix upstream.
>
> Thanks for the heads-up, Ben.ÂÂI'll defer it for 4.2-stable.
>
> I'm thinking that it should also be reverted from the stable kernels
> that already carry it (3.2, 3.13, 3.16, 3.19), unless that complete
> upstream fix is really imminent.ÂÂIs it?

Normally if there's a regression that affects both mainline and stable
branches, we wait for it to be fixed in mainline first.

Ben.

--
Ben Hutchings
Life would be so much easier if we could look at the source code.

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