Re: [Qemu-devel] Linux 3.4, VersatilePB and PCI

[Marc Marí]

El Tue, 13 Jan 2015 10:46:20 +0000
Peter Maydell <address@hidden> escribió:
> On 13 January 2015 at 10:35, Marc Marí <address@hidden>
> wrote:
> > I was fearing that answer :). No, I can't. I want to compare the
> > behaviour of a "normal" Linux 3.4 with another modified Linux 3.4,
> > and the second one is fixed.
> >
> > And is not that ancient, it only has 2.5 years :)
> 
> In that case you'll need to debug the issue like you would
> any other "kernel misbehaving" issue -- figure out what the
> kernel is doing to cause it to print that message, identify
> whether that's because the kernel itself is buggy or because
> QEMU's hardware emulation is buggy, and go from there...
> 
> There were a number of bugfixes applied to the versatile
> PCI controller code at some point after 3.4, so I wouldn't
> be very surprised if the answer turns out to be "this is
> just broken in 3.4".
> 
> In particular, commit 9b0f7e39923 which isn't in 3.4 AFAIK
> basically says "we broke I/O access", which is probably what
> you're running into. I expect you'll need other fixes too.
> 
> So you can try to find and cherry-pick the necessary fixes, which
> could be painful, or you can move to a newer kernel which already
> has them.

Thank you very much. I didn't know where to start looking, so I was
lost. This helps me find my way again.

Thanks
Marc