Hi Saravana,
On Fri, 10 Nov 2023 17:50:07 -0800
Saravana Kannan <saravanak@xxxxxxxxxx> wrote:
> On Thu, Nov 9, 2023 at 11:56 PM Herve Codina <herve.codina@xxxxxxxxxxx> wrote:
> >
> > The commit 3a2dbc510c43 ("driver core: fw_devlink: Don't purge child
> > fwnode's consumer links") introduces the possibility to use the
> > supplier's parent device instead of the supplier itself.
> > In that case the supplier fwnode used is not updated and is no more
> > consistent with the supplier device used.
> >
> > Update the fwnode used to be consistent with the supplier device used.
> >
> > Fixes: 3a2dbc510c43 ("driver core: fw_devlink: Don't purge child fwnode's consumer links")
> > Cc: stable@xxxxxxxxxxxxxxx
> > Signed-off-by: Herve Codina <herve.codina@xxxxxxxxxxx>
> > ---
> > drivers/base/core.c | 12 ++++++++++++
> > 1 file changed, 12 insertions(+)
> >
> > diff --git a/drivers/base/core.c b/drivers/base/core.c
> > index 4d8b315c48a1..17f2568e0a79 100644
> > --- a/drivers/base/core.c
> > +++ b/drivers/base/core.c
> > @@ -2076,6 +2076,18 @@ static int fw_devlink_create_devlink(struct device *con,
> > sup_dev = get_dev_from_fwnode(sup_handle);
> >
> > if (sup_dev) {
> > + /*
> > + * The supplier device may have changed and so, the supplier
> > + * fwnode maybe inconsistent.
> > + * Update the supplier fwnode
> > + */
> > + sup_handle = sup_dev->fwnode;
> > + if (!sup_handle) {
> > + dev_dbg(con, "Not linking %s - fwnode NULL\n",
> > + dev_name(sup_dev));
> > + goto out;
> > + }
> > +
>
> Nack. It's easier to debug when you know what supplier you were
> pointing to in DT that triggered the creation of the device link. The
> parent could be several levels up and multiple supplier links might be
> skipped for various reasons. If they all printed the parent's fwnode,
> it'll be confusing to debug.
In fact, I will remove the check if(!sup_handle) in the next iteration.
Indeed, sup_handle cannot be NULL.
sup_dev is retrieved from fwnode_get_next_parent_dev() or get_dev_from_fwnode().
In both cases, if sup_dev is valid, sup_dev->fwnode is valid too.
So, the check and the dev_dbg() call make no sense.
Best regards,
Hervé
