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

[Kuppuswamy, Sathyanarayanan]

On 10/12/20 2:05 PM, Raj, Ashok wrote:
> On Sun, Oct 11, 2020 at 10:03:40PM -0700, sathyanarayanan.nkuppuswamy@xxxxxxxxx wrote:
> > From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
> >
> > 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@xxxxxxxxxxxxxxx>
> > ---
> >   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

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Sathyanarayanan Kuppuswamy
Linux Kernel Developer