Re: [PATCH AUTOSEL 4.14 52/87] nfp: fail probe if serial or interface id is missing

From: Jakub Kicinski
Date: Mon Sep 17 2018 - 10:03:26 EST


On Mon, 17 Sep 2018 03:02:55 +0000, Sasha Levin wrote:
> From: Jakub Kicinski <jakub.kicinski@xxxxxxxxxxxxx>
>
> [ Upstream commit 18aa5b180f00a10c2f63944b4f0ab116bf8ea19b ]
>
> On some platforms with broken ACPI tables we may not have access
> to the Serial Number PCIe capability. This capability is crucial
> for us for switchdev operation as we use serial number as switch ID,
> and for communication with management FW where interface ID is used.
>
> If we can't determine the Serial Number we have to fail device probe.
>
> Signed-off-by: Jakub Kicinski <jakub.kicinski@xxxxxxxxxxxxx>
> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>

If the problem occurs the driver would usually fail to probe anyway
(e.g. due to missing SR-IOV capability), just without providing any
clear message why. So the patch is not of huge importance, but I'm
not opposed to back porting it.

I should've put this info in the commit message, my bad.