Re: [PATCH] PCI: quirks: add vendor ID for AR9462 card

From: Bjorn Helgaas
Date: Mon Jan 07 2019 - 17:08:17 EST

[+cc Alex, Bharat, LKML]

Hi James,

Thanks for finding this issue and for the patch.

Is there any chance you have a PCIe analyzer and could investigate
what's going on at that level? The bus reset should be fairly similar
to what happens on a cold boot, and obviously *that* works, so I
wonder if we can figure out what the difference here is.

If this is actually broken somehow in the hardware, can you dig up a
hardware erratum and include a URL here?

If there's any chance we could fix or work around this in the kernel,
I'd rather do that than extend this quirk to more devices.

FWIW, here's a similar report, which hasn't been resolved yet:

On Mon, Jan 07, 2019 at 01:32:48PM -0800, James Prestwood wrote:
> This card has similar issues with bus reset as the others present in
> this list.
> Signed-off-by: James Prestwood <james.prestwood@xxxxxxxxxxxxxxx>
> ---
> drivers/pci/quirks.c | 1 +
> 1 file changed, 1 insertion(+)
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index ef7143a274e0..d9d4a95b0309 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -3379,6 +3379,7 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x0030, quirk_no_bus_reset);
> DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x0032, quirk_no_bus_reset);
> DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x003c, quirk_no_bus_reset);
> DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x0033, quirk_no_bus_reset);
> +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x0034, quirk_no_bus_reset);
> /*
> * Root port on some Cavium CN8xxx chips do not successfully complete a bus
> --
> 2.17.1