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

[Alexey Kardashevskiy]

On 19/06/2019 14:27, Sam Bobroff wrote:
> 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 at linux.ibm.com>
>>> Reviewed-by: Alexey Kardashevskiy <aik at 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'd switch them all to already existing dev_dbg/pci_debug rather than
adding pdn_debug as imho it should not have been used in the first place
really...

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

... and if you switch to dev_dbg/pci_debug, I think quite soon you'll
know if it can or cannot 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

-- 
Alexey