EHCI schedule patch for Hardy/Netbooks

[Gustavo Sverzut Barbieri]

On Friday 24 April 2009 11:09:55 Stefan Bader wrote:
> Gustavo Sverzut Barbieri wrote:
> > Hello guys,
>
> Hi Gustavo,
>
> > I asked in #kernel and rtg asked me to mail you, so here it is:
> >
> > Bug (private):
> >     https://bugs.edge.launchpad.net/payson/+bug/309717
>
> If we want to discuss this into the direction from Alan and also if this
> should get into Hardy as a SRU, we will need a public bug for it.
>
> > Patch (backport from mainline 2.6.26, with changes listed below):
> >     http://launchpadlibrarian.net/25896046/ehci-sched.patch
> > Mainline patch:
> >   
> > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit
> >diff_plain;h=b40e43fcc532fa44a375a37d592e32cd0d50fe7a Extra References
> > (comment on above bug):
> >    [1] https://bugs.edge.launchpad.net/payson/+bug/309717/comments/15
> >    [2] https://lists.berlios.de/pipermail/linux-uvc-devel/2008-
> > March/003294.html
> >    [3] http://www.mail-archive.com/linux-uvc-
> > devel at lists.berlios.de/msg02733.html
> >
> >
> > Please consider this backport patch to Hardy as it will fix problems not
> > only on this Toshiba, but other usb video devices and even other usb
> > devices.
> >
> > The difference from mainline is the second half of the patch, which did
> > not apply given differences between .24 and .26 kernel. As I'm no expert
> > in EHCI and as the original patch [2] author (Alan Stern) did the
> > simplified patch before, I suppose that it is okay, but may need further
> > investigation, maybe ask Alan.
>
> I would not say I really understand the exact implications but from the
> code and comments this looks more like an optimization than something
> urgently required.
>
> Would we like to get the whole patch, this would depend on one more patch
> (attached). That one too looks like optimizing away unnecessary workload
> and might also had been improving the situation which the other fix
> addresses. The big downside is that this is USB, not some rarely used
> driver. Any change we make might have an unexpected side effect. And from
> the past we know there is a good chance to find those not before the moment
> the changes go into updates.
>
> So from my view, the risk is already present with just the partial upstream
> patch. If that already fixes the seen problem and we did not find other
> problems with it, I would rather go with that.

Any updates on this?

-- 
Gustavo Sverzut Barbieri
http://profusion.mobi embedded systems / Canonical Contractor
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