Re: [PATCH] igb: fix unused igb_deliver_wake_packet() warning when CONFIG_PM=n

From: Fabio Estevam
Date: Wed Jul 12 2017 - 17:23:40 EST

On Wed, Jul 12, 2017 at 6:09 PM, Dave Hansen
<dave.hansen@xxxxxxxxxxxxxxx> wrote:
> From: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
> I'm seeing warnings on kernel configurations where CONFIG_PM is
> disabled. It happens in 4.12, at least:
> drivers/ethernet/intel/igb/igb_main.c:7988:13: warning: 'igb_deliver_wake_packet' defined but not used [-Wunused-function]
> This is because igb_deliver_wake_packet() is defined outside of
> the #ifdef", but is used only a single time within the #ifdef in
> igb_resume(). Fix it by moving igb_deliver_wake_packet() next to
> igb_resume() inside the #ifdef.
> The diff ends up looking a bit funky here. It *looks* like
> igb_suspend() is getting moved, but that's an artifact of how
> 'diff' sees the changes.
> Cc: Jeff Kirsher <jeffrey.t.kirsher@xxxxxxxxx>
> Cc: intel-wired-lan@xxxxxxxxxxxxxxxx
> Cc: netdev@xxxxxxxxxxxxxxx
> Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>

Seems to be fixed by the following commit in linux-next:

commit 000ba1f2ebf0d6f93b9ae6cfbe5417e66f1b8e8c
Author: Arnd Bergmann <arnd@xxxxxxxx>
Date: Thu Apr 27 21:09:52 2017 +0200

igb: mark PM functions as __maybe_unused

The new wake function is only used by the suspend/resume handlers that
are defined in inside of an #ifdef, which can cause this harmless

drivers/net/ethernet/intel/igb/igb_main.c:7988:13: warning:
'igb_deliver_wake_packet' defined but not used [-Wunused-function]

Removing the #ifdef, instead using a __maybe_unused annotation
simplifies the code and avoids the warning.

Fixes: b90fa8763560 ("igb: Enable reading of wake up packet")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Tested-by: Aaron Brown <aaron.f.brown@xxxxxxxxx>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@xxxxxxxxx>