Linux Virtualization - Jul 2017 - [PATCH net-next] virtio-net: mark PM functions as __maybe_unused

After removing the reset function, the freeze and restore functions
are now unused when CONFIG_PM_SLEEP is disabled:

drivers/net/virtio_net.c:1881:12: error: 'virtnet_restore_up' defined
but not used [-Werror=unused-function]
 static int virtnet_restore_up(struct virtio_device *vdev)
drivers/net/virtio_net.c:1859:13: error: 'virtnet_freeze_down' defined
but not used [-Werror=unused-function]
 static void virtnet_freeze_down(struct virtio_device *vdev)

A more robust way to do this is to remove the #ifdef around the callers
and instead mark them as __maybe_unused. The compiler will now just
silently drop the unused code.

Fixes: 4941d472bf95 ("virtio-net: do not reset during XDP set")
Signed-off-by: Arnd Bergmann <arnd at arndb.de>
---
 drivers/net/virtio_net.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index d4751ce23b4f..1902701e15a9 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -2702,8 +2702,7 @@ static void virtnet_remove(struct virtio_device *vdev)
 	free_netdev(vi->dev);
 }
 
-#ifdef CONFIG_PM_SLEEP
-static int virtnet_freeze(struct virtio_device *vdev)
+static __maybe_unused int virtnet_freeze(struct virtio_device *vdev)
 {
 	struct virtnet_info *vi = vdev->priv;
 
@@ -2714,7 +2713,7 @@ static int virtnet_freeze(struct virtio_device *vdev)
 	return 0;
 }
 
-static int virtnet_restore(struct virtio_device *vdev)
+static __maybe_unused int virtnet_restore(struct virtio_device *vdev)
 {
 	struct virtnet_info *vi = vdev->priv;
 	int err;
@@ -2730,7 +2729,6 @@ static int virtnet_restore(struct virtio_device *vdev)
 
 	return 0;
 }
-#endif
 
 static struct virtio_device_id id_table[] = {
 	{ VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
-- 
2.9.0

On 2017?07?25? 23:35, Arnd Bergmann wrote:
> After removing the reset function, the freeze and restore functions
> are now unused when CONFIG_PM_SLEEP is disabled:
>
> drivers/net/virtio_net.c:1881:12: error: 'virtnet_restore_up'
defined but not used [-Werror=unused-function]
>   static int virtnet_restore_up(struct virtio_device *vdev)
> drivers/net/virtio_net.c:1859:13: error: 'virtnet_freeze_down'
defined but not used [-Werror=unused-function]
>   static void virtnet_freeze_down(struct virtio_device *vdev)
>
> A more robust way to do this is to remove the #ifdef around the callers
> and instead mark them as __maybe_unused. The compiler will now just
> silently drop the unused code.
>
> Fixes: 4941d472bf95 ("virtio-net: do not reset during XDP set")
> Signed-off-by: Arnd Bergmann <arnd at arndb.de>
> ---
>   drivers/net/virtio_net.c | 6 ++----
>   1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index d4751ce23b4f..1902701e15a9 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -2702,8 +2702,7 @@ static void virtnet_remove(struct virtio_device
*vdev)
>   	free_netdev(vi->dev);
>   }
>   
> -#ifdef CONFIG_PM_SLEEP
> -static int virtnet_freeze(struct virtio_device *vdev)
> +static __maybe_unused int virtnet_freeze(struct virtio_device *vdev)
>   {
>   	struct virtnet_info *vi = vdev->priv;
>   
> @@ -2714,7 +2713,7 @@ static int virtnet_freeze(struct virtio_device *vdev)
>   	return 0;
>   }
>   
> -static int virtnet_restore(struct virtio_device *vdev)
> +static __maybe_unused int virtnet_restore(struct virtio_device *vdev)
>   {
>   	struct virtnet_info *vi = vdev->priv;
>   	int err;
> @@ -2730,7 +2729,6 @@ static int virtnet_restore(struct virtio_device
*vdev)
>   
>   	return 0;
>   }
> -#endif
>   
>   static struct virtio_device_id id_table[] = {
>   	{ VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
Acked-by: Jason Wang <jasowang at redhat.com>

From: Arnd Bergmann <arnd at arndb.de>
Date: Tue, 25 Jul 2017 17:35:50 +0200
> After removing the reset function, the freeze and restore functions
> are now unused when CONFIG_PM_SLEEP is disabled:
> 
> drivers/net/virtio_net.c:1881:12: error: 'virtnet_restore_up'
defined but not used [-Werror=unused-function]
>  static int virtnet_restore_up(struct virtio_device *vdev)
> drivers/net/virtio_net.c:1859:13: error: 'virtnet_freeze_down'
defined but not used [-Werror=unused-function]
>  static void virtnet_freeze_down(struct virtio_device *vdev)
> 
> A more robust way to do this is to remove the #ifdef around the callers
> and instead mark them as __maybe_unused. The compiler will now just
> silently drop the unused code.
> 
> Fixes: 4941d472bf95 ("virtio-net: do not reset during XDP set")
> Signed-off-by: Arnd Bergmann <arnd at arndb.de>
Applied, thanks.