powerpc/pci sysdata batch hangs G5 boot

powerpc/pci sysdata batch hangs G5 boot

[Hugh Dickins]

Hi Grant,

I've been unable to boot mmotm on the G5 for a few weeks; and now that
the problem has reached Linus, I've bisected and it converges on your:

commit b5d937de0367d26f65b9af1aef5f2c34c1939be0
    powerpc/pci: Make both ppc32 and ppc64 use sysdata for pci_controller
   
    Currently, ppc32 uses sysdata for the pci_controller pointer, and
    ppc64 uses it to hold the device_node pointer.  This patch moves the
    of_node pointer into (struct pci_bus*)->dev.of_node and
    (struct pci_dev*)->dev.of_node so that sysdata can be converted to always
    use the pci_controller pointer instead.  It also fixes up the
    allocating of pci devices so that the of_node pointer gets assigned
    consistently and increments the ref count.

The last message I see on screen when booting is
mpic: ISU size: 124, shift: 7, mask: 7f

Usually that would be followed by
mpic: Initializing for 124 sources

but with your commit it just hangs; revert that commit,
from mmotm or from Linus's current git, and all is fine.

Config available privately on request.  Noticing that patch is a
PPC OF PCI thing, and that I have CONFIG_PPC_OF_PLATFORM_PCI off,
I did try switching that on, but it made no difference.

Thanks,
Hugh

Re: powerpc/pci sysdata batch hangs G5 boot

[Grant Likely]

On Sat, Mar 19, 2011 at 9:41 PM, Hugh Dickins <hughd@google.com> wrote:
> Hi Grant,
>
> I've been unable to boot mmotm on the G5 for a few weeks; and now that
> the problem has reached Linus, I've bisected and it converges on your:
>
> commit b5d937de0367d26f65b9af1aef5f2c34c1939be0
> =A0 =A0powerpc/pci: Make both ppc32 and ppc64 use sysdata for pci_control=
ler

Hi Hugh,

Thanks for the testing.  I don't have access to a G5 unfortunately.
Are you able to capture the good/bad console output and send it to me?
 A digital photo would be fine if you can't grab the raw text.  Add
#define DEBUG to the top of arch/powerpc/kernel/pci-common.c above the
#includes too if you don't mind.

I'm investigating on my end.  I suspect that I've messed up retrieval
of the hose pointer.

Thanks,
g.

Re: powerpc/pci sysdata batch hangs G5 boot

[Benjamin Herrenschmidt]

On Sun, 2011-03-20 at 00:25 -0600, Grant Likely wrote:
> On Sat, Mar 19, 2011 at 9:41 PM, Hugh Dickins <hughd@google.com> wrote:
> > Hi Grant,
> >
> > I've been unable to boot mmotm on the G5 for a few weeks; and now that
> > the problem has reached Linus, I've bisected and it converges on your:
> >
> > commit b5d937de0367d26f65b9af1aef5f2c34c1939be0
> >    powerpc/pci: Make both ppc32 and ppc64 use sysdata for pci_controller
> 
> Hi Hugh,
> 
> Thanks for the testing.  I don't have access to a G5 unfortunately.
> Are you able to capture the good/bad console output and send it to me?
>  A digital photo would be fine if you can't grab the raw text.  Add
> #define DEBUG to the top of arch/powerpc/kernel/pci-common.c above the
> #includes too if you don't mind.
> 
> I'm investigating on my end.  I suspect that I've messed up retrieval
> of the hose pointer.

Hrm, you merged that already ? I would have liked to have a chance to at
least test and review properly...

Oh well, I have G5's here, I'll see if I can find what's wrong tomorrow.

Cheers,
Ben.