Re: [PATCH -next] drivers/base/power: fix build error without SYSFS

[Christian Brauner]

On Mon, Mar 02, 2020 at 05:29:18PM +0800, Hongbo Yao wrote:
> If CONFIG_SYSFS=n, the following error is seen while building 
> drivers/base/power/sysfs.c:
> 
> drivers/base/power/sysfs.c: In function dpm_sysfs_change_owner:
> drivers/base/power/sysfs.c:708:44: error: passing argument 2 of
> sysfs_group_change_owner from incompatible pointer type
> [-Werror=incompatible-pointer-types]
>   rc = sysfs_group_change_owner(&dev->kobj, &pm_attr_group, kuid, kgid);
>                                             ^
> In file included from ./include/linux/kobject.h:20:0,
>                  from ./include/linux/device.h:17,
>                  from drivers/base/power/sysfs.c:3:
> ./include/linux/sysfs.h:564:19: note: expected const struct
> attribute_group ** but argument is of type const struct attribute_group *
> 
> dpm_sysfs_change_owner() should only used when CONFIG_SYSFS is
> defined.
> 
> Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
> Fixes: 3b52fc5d7876 ("drivers/base/power: add dpm_sysfs_change_owner()")
> Signed-off-by: Hongbo Yao <yaohongbo@xxxxxxxxxx>

Thanks for catching this!
An organizational comment first. The series this belongs to is sitting
in Dave Miller's net-next tree. So this fix needs to go through his tree
to. This just means, you should Cc the netdev kernel mailing list and
append make the subject
[PATCH net-next] drivers/base/power: fix build error without SYSFS
.

But about the fix. It strikes me as odd that this fails in pm_attr_group
since dpm_sysfs_add() doesn't but also unconditionally accesses pm_attr_group.

Christian