Re: [PATCH 4.9 37/62] UAS: Revert commit 3ae62a42090f ("UAS: fix alignment of scatter/gather segments")

Greg Kroah-Hartman
2019-11-06T11:17:11Z

On Wed, Nov 06, 2019 at 08:45:02AM +0100, Oliver Neukum wrote:
> Am Dienstag, den 05.11.2019, 19:11 -0500 schrieb Sasha Levin:
> > On Tue, Nov 05, 2019 at 03:31:08PM +0100, Oliver Neukum wrote:
> > > Am Montag, den 04.11.2019, 22:44 +0100 schrieb Greg Kroah-Hartman:
> > > > All the host controllers capable of SuperSpeed operation can
> > > > handle fully general SG;
> > > >
> > > > Since commit ea44d190764b ("usbip: Implement SG support to
> > > > vhci-hcd and stub driver") was merged, the USB/IP driver can
> > > > also handle SG.
> > >
> > > Not in 4.9.x. AFAICT the same story as 4.4.x
> > > The patch is not strictly needed, but breaks UAS over usbip.
> >
> > It's in 4.9 since April this year... Same story for 4.4.
>
> Hi,
>
> now I am confused. Neither looking at the logs nor the source
> I can see the commit. Top commit is
> 9e48f0c28dd505e39bd136ec92a042b311b127c6
> of git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git
>
> I am sorry for being obnoxious here and it is entirely possible that
> I am stupid, but this is a discrepancy that needs to be resolved.

Commit 3ae62a42090f ("UAS: fix alignment of scatter/gather segments") is
the patch that is being reverted here, and it is in the following kernel
releases:
4.4.180 4.9.175 4.14.118 4.19.42 5.0.15 5.1.1 5.2
And it is causing known issues, so we should revert it.

Now if usbip breaks with this revert, we should add the newer patch that
keeps it working properly, is that what you are thinking that
ea44d190764b ("usbip: Implement SG support to vhci-hcd and stub driver")
is?

thanks,

greg k-h