On Tue, Sep 29, 2020 at 02:25:33PM +0200, Greg Kroah-Hartman wrote: > On Tue, Sep 29, 2020 at 01:58:08PM +0200, [email protected] wrote: > > From: Lars Poeschel <[email protected]> > > > > This removes an assignment in device_add. It assigned the parent > > kobject to the kobject of the new device. This is not necessary, > > because the call to kobject_add a few lines later also does this same > > assignment. > > > > Signed-off-by: Lars Poeschel <[email protected]> > > --- > > drivers/base/core.c | 4 +--- > > 1 file changed, 1 insertion(+), 3 deletions(-) > > > > diff --git a/drivers/base/core.c b/drivers/base/core.c > > index bb5806a2bd4c..03b5396cd192 100644 > > --- a/drivers/base/core.c > > +++ b/drivers/base/core.c > > @@ -2847,8 +2847,6 @@ int device_add(struct device *dev) > > error = PTR_ERR(kobj); > > goto parent_error; > > } > > - if (kobj) > > - dev->kobj.parent = kobj; > > > > /* use parent numa_node */ > > if (parent && (dev_to_node(dev) == NUMA_NO_NODE)) > > @@ -2856,7 +2854,7 @@ int device_add(struct device *dev) > > > > /* first, register with generic layer. */ > > /* we require the name to be set before, and pass NULL */ > > - error = kobject_add(&dev->kobj, dev->kobj.parent, NULL); > > + error = kobject_add(&dev->kobj, kobj, NULL); > > That's very subtle, and might not really be correct for all users, have > you checked?
Of course I have not checked for all users ;-), but I have checked this for my system and I did not notice any difference. My system is an arm based board that does several hundreds of calls to the device_add function per kernel bootup. > Anyway, I'd rather leave this as-is if possible, as we know this works > correctly, and it is not going to save any time/energy to remove that > assignment, right? Of course it's up to you to leave this as is. Pure binary size drops from 0x784 to 0x778 (12 bytes) with this patch for the device_add function on arm with gcc 10.2.0. So this saves a tiny amount of size and energy. If it's worth that, I don't know. And not to mention the time/energy you save when some time some random guy again stubles upon this, sends you a patch and then you have to reply. ;-) Ok, as said:Taking this is up to you. I can also live without this. Regards, Lars
