Re: [PATCH v7 1/1] PCI: pciehp: Ignore link events when there is a fatal error pending

[Lukas Wunner <lukas@wunner.de>]

On Mon, Aug 06, 2018 at 01:21:03PM +0530, poza@codeaurora.org wrote:
> On 2018-08-06 04:21, Sinan Kaya wrote:
> >+bool pcie_wait_fatal_error_clear(struct pci_dev *pdev, u32 usrmask)
> >+{
> >+	int timeout = 1000;
> >+	bool ret;
> >+
> >+	for (;;) {
> >+		ret = pcie_fatal_error_pending(pdev, usrmask);
> >+		if (ret == false)
> >+			return true;
> >+		if (timeout <= 0)
> >+			break;
> >+		msleep(20);
> >+		timeout -= 20;
> I assume that this timeout will come into effect if
> 1) AER/DPC takes longer time than 1 sec for recovery.
> 2) Lets us say both AER and DPC are disabled....are we going to wait for
> this timeout before HP can take over ?

If CONFIG_PCIEAER is disabled, pdev->aer_cap will not be set because
it is populated in pci_aer_init().

pcie_fatal_error_pending(), as introduced by this patch, returns false
if pdev->aer_cap is not set.  So pciehp will fall back to a cold reset
if CONFIG_PCIEAER is disabled.

I'm not seeing a similar check for CONFIG_PCIE_DPC=n in this patch,
but I'm not familiar enough with PCIe error recovery to know if such
a check is at all needed.

Thanks,

Lukas