Re: [PATCH v4 1/2] PCI/ERR: Call pci_bus_reset() before calling ->slot_reset() callback

["Kuppuswamy, Sathyanarayanan" <sathyanarayanan.kuppuswamy@linux.intel.com>]

On 10/12/20 2:05 PM, Raj, Ashok wrote:
> On Sun, Oct 11, 2020 at 10:03:40PM -0700, sathyanarayanan.nkuppuswamy@gmail.com wrote:
>> From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
>>
>> Currently if report_error_detected() or report_mmio_enabled()
>> functions requests PCI_ERS_RESULT_NEED_RESET, current
>> pcie_do_recovery() implementation does not do the requested
>> explicit device reset, but instead just calls the
>> report_slot_reset() on all affected devices. Notifying about the
>> reset via report_slot_reset() without doing the actual device
>> reset is incorrect. So call pci_bus_reset() before triggering
>> ->slot_reset() callback.
>>
>> Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
>> ---
>>   drivers/pci/pcie/err.c | 6 +-----
>>   1 file changed, 1 insertion(+), 5 deletions(-)
>>
>> diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
>> index c543f419d8f9..067c58728b88 100644
>> --- a/drivers/pci/pcie/err.c
>> +++ b/drivers/pci/pcie/err.c
>> @@ -181,11 +181,7 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
>>   	}
>>   
>>   	if (status == PCI_ERS_RESULT_NEED_RESET) {
>> -		/*
>> -		 * TODO: Should call platform-specific
>> -		 * functions to reset slot before calling
>> -		 * drivers' slot_reset callbacks?
>> -		 */
>> +		pci_reset_bus(dev);
> 
> pci_reset_bus() returns an error, do you need to consult that before
> unconditionally setting PCI_ERS_RESULT_RECOVERED?
Good point. I will fix this in next version.
> 
>>   		status = PCI_ERS_RESULT_RECOVERED;
>>   		pci_dbg(dev, "broadcast slot_reset message\n");
>>   		pci_walk_bus(bus, report_slot_reset, &status);
>> -- 
>> 2.17.1
>>

-- 
Sathyanarayanan Kuppuswamy
Linux Kernel Developer