Re: [PATCH v2 3/6] powerpc/eeh: Improve debug messages around device addition

[Sam Bobroff <sbobroff@linux.ibm.com>]

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On Tue, Jun 11, 2019 at 03:47:58PM +1000, Alexey Kardashevskiy wrote:
> 
> 
> On 07/05/2019 14:30, Sam Bobroff wrote:
> > Also remove useless comment.
> > 
> > Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
> > Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> > ---
> >  arch/powerpc/kernel/eeh.c                    |  2 +-
> >  arch/powerpc/platforms/powernv/eeh-powernv.c | 14 ++++++++----
> >  arch/powerpc/platforms/pseries/eeh_pseries.c | 23 +++++++++++++++-----
> >  3 files changed, 28 insertions(+), 11 deletions(-)
> > 
> > diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
> > index 8d3c36a1f194..b14d89547895 100644
> > --- a/arch/powerpc/kernel/eeh.c
> > +++ b/arch/powerpc/kernel/eeh.c
> > @@ -1291,7 +1291,7 @@ void eeh_add_device_late(struct pci_dev *dev)
> >  	pdn = pci_get_pdn_by_devfn(dev->bus, dev->devfn);
> >  	edev = pdn_to_eeh_dev(pdn);
> >  	if (edev->pdev == dev) {
> > -		pr_debug("EEH: Already referenced !\n");
> > +		pr_debug("EEH: Device %s already referenced!\n", pci_name(dev));
> >  		return;
> >  	}
> >  
> > diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c
> > index 6fc1a463b796..0e374cdba961 100644
> > --- a/arch/powerpc/platforms/powernv/eeh-powernv.c
> > +++ b/arch/powerpc/platforms/powernv/eeh-powernv.c
> > @@ -50,10 +50,7 @@ void pnv_pcibios_bus_add_device(struct pci_dev *pdev)
> >  	if (!pdev->is_virtfn)
> >  		return;
> >  
> > -	/*
> > -	 * The following operations will fail if VF's sysfs files
> > -	 * aren't created or its resources aren't finalized.
> > -	 */
> > +	pr_debug("%s: EEH: Setting up device %s.\n", __func__, pci_name(pdev));
> 
> 
> dev_dbg() seems more appropriate.

Oh! It does, or even pci_debug() :-)

I'll change it if I need to do another version, otherwise I'll clean it
up later.

> >  	eeh_add_device_early(pdn);
> >  	eeh_add_device_late(pdev);
> >  	eeh_sysfs_add_device(pdev);
> > @@ -397,6 +394,10 @@ static void *pnv_eeh_probe(struct pci_dn *pdn, void *data)
> >  	int ret;
> >  	int config_addr = (pdn->busno << 8) | (pdn->devfn);
> >  
> > +	pr_debug("%s: probing %04x:%02x:%02x.%01x\n",
> > +		__func__, hose->global_number, pdn->busno,
> > +		PCI_SLOT(pdn->devfn), PCI_FUNC(pdn->devfn));
> > +
> >  	/*
> >  	 * When probing the root bridge, which doesn't have any
> >  	 * subordinate PCI devices. We don't have OF node for
> > @@ -491,6 +492,11 @@ static void *pnv_eeh_probe(struct pci_dn *pdn, void *data)
> >  	/* Save memory bars */
> >  	eeh_save_bars(edev);
> >  
> > +	pr_debug("%s: EEH enabled on %02x:%02x.%01x PHB#%x-PE#%x\n",
> > +		__func__, pdn->busno, PCI_SLOT(pdn->devfn),
> > +		PCI_FUNC(pdn->devfn), edev->pe->phb->global_number,
> > +		edev->pe->addr);
> > +
> >  	return NULL;
> >  }
> >  
> > diff --git a/arch/powerpc/platforms/pseries/eeh_pseries.c b/arch/powerpc/platforms/pseries/eeh_pseries.c
> > index 7aa50258dd42..ae06878fbdea 100644
> > --- a/arch/powerpc/platforms/pseries/eeh_pseries.c
> > +++ b/arch/powerpc/platforms/pseries/eeh_pseries.c
> > @@ -65,6 +65,8 @@ void pseries_pcibios_bus_add_device(struct pci_dev *pdev)
> >  	if (!pdev->is_virtfn)
> >  		return;
> >  
> > +	pr_debug("%s: EEH: Setting up device %s.\n", __func__, pci_name(pdev));
> > +
> >  	pdn->device_id  =  pdev->device;
> >  	pdn->vendor_id  =  pdev->vendor;
> >  	pdn->class_code =  pdev->class;
> > @@ -251,6 +253,10 @@ static void *pseries_eeh_probe(struct pci_dn *pdn, void *data)
> >  	int enable = 0;
> >  	int ret;
> >  
> > +	pr_debug("%s: probing %04x:%02x:%02x.%01x\n",
> > +		__func__, pdn->phb->global_number, pdn->busno,
> > +		PCI_SLOT(pdn->devfn), PCI_FUNC(pdn->devfn));
> > +
> >  	/* Retrieve OF node and eeh device */
> >  	edev = pdn_to_eeh_dev(pdn);
> >  	if (!edev || edev->pe)
> > @@ -294,7 +300,12 @@ static void *pseries_eeh_probe(struct pci_dn *pdn, void *data)
> >  
> >  	/* Enable EEH on the device */
> >  	ret = eeh_ops->set_option(&pe, EEH_OPT_ENABLE);
> > -	if (!ret) {
> > +	if (ret) {
> > +		pr_debug("%s: EEH failed to enable on %02x:%02x.%01x PHB#%x-PE#%x (code %d)\n",
> > +			__func__, pdn->busno, PCI_SLOT(pdn->devfn),
> > +			PCI_FUNC(pdn->devfn), pe.phb->global_number,
> > +			pe.addr, ret);
> > +	} else {
> 
> 
> edev!=NULL here so you could do dev_dbg(&edev->pdev->dev,...) and skip
> PCI_SLOT/PCI_FUNC. Or is (edev!=NULL && edev->pdev==NULL) possible (it
> could be, just asking)?

I can see that edev will be non-NULL here, but that pr_debug() pattern
(using the PDN information to form the PCI address) is quite common
across the EEH code, so I think rather than changing a couple of
specific cases, I should do a separate cleanup patch and introduce
something like pdn_debug(pdn, "...."). What do you think?

(I don't know exactly when edev->pdev can be NULL.)

> 
> >  		/* Retrieve PE address */
> >  		edev->pe_config_addr = eeh_ops->get_pe_addr(&pe);
> >  		pe.addr = edev->pe_config_addr;
> > @@ -310,11 +321,6 @@ static void *pseries_eeh_probe(struct pci_dn *pdn, void *data)
> >  		if (enable) {
> >  			eeh_add_flag(EEH_ENABLED);
> >  			eeh_add_to_parent_pe(edev);
> > -
> > -			pr_debug("%s: EEH enabled on %02x:%02x.%01x PHB#%x-PE#%x\n",
> > -				__func__, pdn->busno, PCI_SLOT(pdn->devfn),
> > -				PCI_FUNC(pdn->devfn), pe.phb->global_number,
> > -				pe.addr);
> >  		} else if (pdn->parent && pdn_to_eeh_dev(pdn->parent) &&
> >  			   (pdn_to_eeh_dev(pdn->parent))->pe) {
> >  			/* This device doesn't support EEH, but it may have an
> > @@ -323,6 +329,11 @@ static void *pseries_eeh_probe(struct pci_dn *pdn, void *data)
> >  			edev->pe_config_addr = pdn_to_eeh_dev(pdn->parent)->pe_config_addr;
> >  			eeh_add_to_parent_pe(edev);
> >  		}
> > +		pr_debug("%s: EEH %s on %02x:%02x.%01x PHB#%x-PE#%x (code %d)\n",
> > +			__func__, (enable ? "enabled" : "unsupported"),
> > +			pdn->busno, PCI_SLOT(pdn->devfn),
> > +			PCI_FUNC(pdn->devfn), pe.phb->global_number,
> > +			pe.addr, ret);
> 
> Same here. I understand though this one is a cut-n-paste :)
> 
> 
> >  	}
> >  
> >  	/* Save memory bars */
> > 
> 
> -- 
> Alexey

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