Subject: Re: [PATCH 3/3] edac/85xx: Enable the EDAC PCI err driver by device_initcall

From: Scott Wood <[email-masked]>
Date: Fri, 28 Sep 2012 12:35:17 -0500

On 09/27/2012 05:33:26 PM, Kumar Gala wrote:
>=20
> On Sep 27, 2012, at 4:51 PM, Scott Wood wrote:
>=20
> > On 09/27/2012 04:45:08 PM, Gala Kumar-B11780 wrote:
> >> On Sep 27, 2012, at 11:09 AM, Scott Wood wrote:
> >>> On 09/27/2012 02:02:03 PM, Chunhe Lan wrote:
> >>>> Original process of call:
> >>>> 	The mpc85xx_pci_err_probe function completes to been registered
> >>>> 	and enabled of EDAC PCI err driver at the latter time stage of
> >>>> 	kernel boot in the mpc85xx_edac.c.
> >>>> Current process of call:
> >>>> 	The mpc85xx_pci_err_probe function completes to been registered
> >>>> 	and enabled of EDAC PCI err driver at the first	time stage of
> >>>> 	kernel boot in the fsl_pci.c.
> >>>> So in this case the following error messages appear in the boot =20
> log:
> >>>>   PCI: Probing PCI hardware
> >>>>   pci 0000:00:00.0: ignoring class b20 (doesn't match header =20
> type 01)
> >>>>   PCIE error(s) detected
> >>>>   PCIE ERR_DR register: 0x00020000
> >>>>   PCIE ERR_CAP_STAT register: 0x80000001
> >>>>   PCIE ERR_CAP_R0 register: 0x00000800
> >>>>   PCIE ERR_CAP_R1 register: 0x00000000
> >>>>   PCIE ERR_CAP_R2 register: 0x00000000
> >>>>   PCIE ERR_CAP_R3 register: 0x00000000
> >>>> Because the EDAC PCI err driver is registered and enabled =20
> earlier than
> >>>> original point of call. But at this point of time, PCI hardware =20
> is not
> >>>> probed and initialized, and it is in unknowable state.
> >>>> So, move enable function into mpc85xx_pci_err_en which is called =20
> at the
> >>>> middle time stage of kernel boot and after PCI hardware is =20
> probed and
> >>>> initialized by device_initcall in the fsl_pci.c.
> >>>> Signed-off-by: Chunhe Lan <[email-masked]>
> >>>> ---
> >>>> arch/powerpc/sysdev/fsl_pci.c |   12 ++++++++++
> >>>> arch/powerpc/sysdev/fsl_pci.h |    5 ++++
> >>>> drivers/edac/mpc85xx_edac.c   |   47 =20
> ++++++++++++++++++++++++++++------------
> >>>> 3 files changed, 50 insertions(+), 14 deletions(-)
> >>>> diff --git a/arch/powerpc/sysdev/fsl_pci.c =20
> b/arch/powerpc/sysdev/fsl_pci.c
> >>>> index 3d6f4d8..a591965 100644
> >>>> --- a/arch/powerpc/sysdev/fsl_pci.c
> >>>> +++ b/arch/powerpc/sysdev/fsl_pci.c
> >>>> @@ -904,4 +904,16 @@ static int __init fsl_pci_init(void)
> >>>> 	return platform_driver_register(&fsl_pci_driver);
> >>>> }
> >>>> arch_initcall(fsl_pci_init);
> >>>> +
> >>>> +static int __init fsl_pci_err_en(void)
> >>>> +{
> >>>> +	struct device_node *np;
> >>>> +
> >>>> +	for_each_node_by_type(np, "pci")
> >>>> +		if (of_match_node(pci_ids, np))
> >>>> +			mpc85xx_pci_err_en(np);
> >>>> +
> >>>> +	return 0;
> >>>> +}
> >>>> +device_initcall(fsl_pci_err_en);
> >>>
> >>> Why can't you call this from the normal PCIe controller init, =20
> instead of searching for the node independently?
> >> Don't we have this now with mpc85xx_pci_err_probe() ??
> >
> > What do you mean by "this"?
>=20
> I'm saying don't we replace fsl_pci_err_en() with =20
> mpc85xx_pci_err_probe()...
>=20
> I need to look at this more, but not clear why mpc85xx_pci_err_en() =20
> can just be part of mpc85xx_pci_err_probe()

OK, I was confused -- I thought the point was to make it happen =20
earlier, not later.  The changelog is not clear at all.

Don't we want to be able to capture errors that happen during PCI =20
driver initialization, though?

-Scott=