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

[Christian Borntraeger <borntraeger@de.ibm.com>]

On 12/18/2017 09:52 AM, Thomas Huth wrote:
> On 18.12.2017 09:37, Christian Borntraeger wrote:
>> We need to disable the pm callbacks if CONFIG_PM is not set.
>>
>> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
>> ---
>> 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.