Re: [PATCH] virtio/s390: fixup for implement PM operations for virtio_ccw

On 12/18/2017 09:52 AM, Thomas Huth wrote:

On 18.12.2017 09:37, Christian Borntraeger wrote:

quoted

We need to disable the pm callbacks if CONFIG_PM is not set.

Signed-off-by: Christian Borntraeger <redacted>
---
Cornelia, you might want to squash this into the original commit.

 drivers/s390/virtio/virtio_ccw.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c
index 330b3fa3430a..985184ebda45 100644
--- a/drivers/s390/virtio/virtio_ccw.c
+++ b/drivers/s390/virtio/virtio_ccw.c

@@ -1315,6 +1315,7 @@ static struct ccw_device_id virtio_ids[] = {
 	{},
 };
 
+#ifdef CONFIG_PM_SLEEP
 static int virtio_ccw_freeze(struct ccw_device *cdev)
 {
 	struct virtio_ccw_device *vcdev = dev_get_drvdata(&cdev->dev);

@@ -1333,6 +1334,7 @@ static int virtio_ccw_restore(struct ccw_device *cdev)
 
 	return virtio_device_restore(&vcdev->vdev);
 }
+#endif
 
 static struct ccw_driver virtio_ccw_driver = {
 	.driver = {

@@ -1346,9 +1348,11 @@ static struct ccw_driver virtio_ccw_driver = {
 	.set_online = virtio_ccw_online,
 	.notify = virtio_ccw_cio_notify,
 	.int_class = IRQIO_VIR,
+#ifdef CONFIG_PM_SLEEP
 	.freeze = virtio_ccw_freeze,
 	.thaw = virtio_ccw_restore,
 	.restore = virtio_ccw_restore,
+#endif
 };

Some other drivers rather seem to test CONFIG_HIBERNATE_CALLBACKS ...
would that be a more appropriate config flag here?

The virtio code uses CONFIG_PM_SLEEP (and we call that code). 

See
include/linux/virtio.h

c6716bae52f97 (Michael S. Tsirkin 2014-10-14 10:40:35 +1030 155) #ifdef CONFIG_PM_SLEEP
c6716bae52f97 (Michael S. Tsirkin 2014-10-14 10:40:35 +1030 156) int virtio_device_freeze(struct virtio_device *dev);
c6716bae52f97 (Michael S. Tsirkin 2014-10-14 10:40:35 +1030 157) int virtio_device_restore(struct virtio_device *dev);
c6716bae52f97 (Michael S. Tsirkin 2014-10-14 10:40:35 +1030 158) #endif



So I think CONFIG_PM_SLEEP is the best fit.