From: David Hildenbrand <david@xxxxxxxxxx> [ Upstream commit 7d8212747435c534c8d564fbef4541a463c976ff ] When unloading the module, one gets ------------[ cut here ]------------ Device 'cmm0' does not have a release() function, it is broken and must be fixed. See Documentation/kobject.txt. WARNING: CPU: 0 PID: 19308 at drivers/base/core.c:1244 .device_release+0xcc/0xf0 ... We only have one static fake device. There is nothing to do when releasing the device (via cmm_exit()). Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20191031142933.10779-2-david@xxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- arch/powerpc/platforms/pseries/cmm.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/powerpc/platforms/pseries/cmm.c b/arch/powerpc/platforms/pseries/cmm.c index 25427a48feae3..502ebcc6c3cbe 100644 --- a/arch/powerpc/platforms/pseries/cmm.c +++ b/arch/powerpc/platforms/pseries/cmm.c @@ -425,6 +425,10 @@ static struct bus_type cmm_subsys = { .dev_name = "cmm", }; +static void cmm_release_device(struct device *dev) +{ +} + /** * cmm_sysfs_register - Register with sysfs * @@ -440,6 +444,7 @@ static int cmm_sysfs_register(struct device *dev) dev->id = 0; dev->bus = &cmm_subsys; + dev->release = cmm_release_device; if ((rc = device_register(dev))) goto subsys_unregister; -- 2.20.1