Re: [PATCH NEXT 6/6] PCI/PORTDRV: Remove ERR_FATAL handling from pcie_portdrv_slot_reset()

Bjorn Helgaas
2018-06-07T21:34:54Z

On Thu, Jun 07, 2018 at 07:18:03PM +0530, poza@codeaurora.org wrote:
> On 2018-06-07 11:30, Oza Pawandeep wrote:
> > We are handling ERR_FATAL by resetting the Link in software,skipping the
> > driver pci_error_handlers callbacks, removing the devices from the PCI
> > subsystem, and re-enumerating, as a result of that, no more calling
> > pcie_portdrv_slot_reset in ERR_FATAL case.
> >
> > Signed-off-by: Oza Pawandeep <poza@codeaurora.org>
> >
> > diff --git a/drivers/pci/pcie/portdrv_pci.c
> > b/drivers/pci/pcie/portdrv_pci.c
> > index 973f1b8..92f5d330 100644
> > --- a/drivers/pci/pcie/portdrv_pci.c
> > +++ b/drivers/pci/pcie/portdrv_pci.c
> > @@ -42,17 +42,6 @@ __setup("pcie_ports=", pcie_port_setup);
> >
> > /* global data */
> >
> > -static int pcie_portdrv_restore_config(struct pci_dev *dev)
> > -{
> > - int retval;
> > -
> > - retval = pci_enable_device(dev);
> > - if (retval)
> > - return retval;
> > - pci_set_master(dev);
> > - return 0;
> > -}
> > -
> > #ifdef CONFIG_PM
> > static int pcie_port_runtime_suspend(struct device *dev)
> > {
> > @@ -162,14 +151,6 @@ static pci_ers_result_t
> > pcie_portdrv_mmio_enabled(struct pci_dev *dev)
> >
> > static pci_ers_result_t pcie_portdrv_slot_reset(struct pci_dev *dev)
> > {
> > - /* If fatal, restore cfg space for possible link reset at upstream */
> > - if (dev->error_state == pci_channel_io_frozen) {
> > - dev->state_saved = true;
> > - pci_restore_state(dev);
> > - pcie_portdrv_restore_config(dev);
> > - pci_enable_pcie_error_reporting(dev);
> > - }
> > -
> > return PCI_ERS_RESULT_RECOVERED;
> > }
>
>
> Hi Bjorn,
>
> the above patch removes ERR_FATAL handling from pcie_portdrv_slot_reset()
> because now we are handling ERR_FATAL differently than before.
>
> I tried to dig into pcie_portdrv_slot_reset() handling for ERR_FATAL case
> where it
> restores the config space, enable device, set master and enable error
> reporting....
> and as far as I understand this is being done for upstream link (bridges
> etc..)
>
> why was it done at the first point (I checked the commit description, but
> could not really get it)
> and do we need to handle the same thing in ERR_FATAL now ?

You mean 4bf3392e0bf5 ("PCI-Express AER implemetation: pcie_portdrv
error handler"), which added pcie_portdrv_slot_reset()? I agree, that
commit log has no useful information. I don't know any of the history
behind it.