[PATCH v2 1/1] driver core: Keep the supplier fwnode consistent with the device

[PATCH v2 1/1] driver core: Keep the supplier fwnode consistent with the device

[Herve Codina]

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@vger.kernel.org
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
---
Changes v1 -> v2:
  Remove sup_handle check and related pr_debug() call as sup_handle cannot be
  invalid if sup_dev is valid.

 drivers/base/core.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 4d8b315c48a1..2f6a21b908ec 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -2076,6 +2076,13 @@ 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 it's one of those drivers that don't actually bind to
 		 * their device using driver core, then don't wait on this
-- 
2.41.0

Re: [PATCH v2 1/1] driver core: Keep the supplier fwnode consistent with the device

[Saravana Kannan]

On Mon, Nov 13, 2023 at 5:30 AM Herve Codina <herve.codina@bootlin.com> 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.

Looks like you missed this comment from my previous reply.

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.

It can get confusing real quick otherwise.

-Saravana

>
> 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@vger.kernel.org
> Signed-off-by: Herve Codina <herve.codina@bootlin.com>
> ---
> Changes v1 -> v2:
>   Remove sup_handle check and related pr_debug() call as sup_handle cannot be
>   invalid if sup_dev is valid.
>
>  drivers/base/core.c | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index 4d8b315c48a1..2f6a21b908ec 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -2076,6 +2076,13 @@ 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 it's one of those drivers that don't actually bind to
>                  * their device using driver core, then don't wait on this
> --
> 2.41.0
>

Re: [PATCH v2 1/1] driver core: Keep the supplier fwnode consistent with the device

[Herve Codina]

Hi Saravana,

On Mon, 13 Nov 2023 12:09:43 -0800
Saravana Kannan <saravanak@google.com> wrote:

> On Mon, Nov 13, 2023 at 5:30 AM Herve Codina <herve.codina@bootlin.com> 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.  
> 
> Looks like you missed this comment from my previous reply.
> 
> 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.
> 
> It can get confusing real quick otherwise.

Sorry,
In the next iteration, I will keep the original supplier handle for
debug prints.

Regards,
Hervé