[RFC PATCH v1 0/2] fw_devlink overlay fix

[RFC PATCH v1 0/2] fw_devlink overlay fix

[Saravana Kannan]

Don't bother review this patch. It needs to be refactored better once I
know it works.

Geert and Herve,

This patch serious should hopefully fix both of your use cases. Can you
please check to make sure the device links created to/from the overlay
devices are to/from the right ones?

I've only compile tested it. If I made some obvious mistake, feel free
to fix it and give it a shot.

Cc: Rob Herring <robh@kernel.org>

Thanks,
Saravana

Saravana Kannan (2):
  Revert "treewide: Fix probing of devices in DT overlays"
  of: dynamic: Fix probing of overlay devices

 drivers/base/core.c       | 10 ++++++++++
 drivers/bus/imx-weim.c    |  6 ------
 drivers/i2c/i2c-core-of.c |  5 -----
 drivers/of/dynamic.c      |  9 ++++++++-
 drivers/of/platform.c     |  5 -----
 drivers/spi/spi.c         |  5 -----
 include/linux/fwnode.h    |  2 ++
 7 files changed, 20 insertions(+), 22 deletions(-)

-- 
2.44.0.478.gd926399ef9-goog

[RFC PATCH v1 1/2] Revert "treewide: Fix probing of devices in DT overlays"

[Saravana Kannan]

This reverts commit 1a50d9403fb90cbe4dea0ec9fd0351d2ecbd8924.
---
 drivers/bus/imx-weim.c    | 6 ------
 drivers/i2c/i2c-core-of.c | 5 -----
 drivers/of/dynamic.c      | 1 -
 drivers/of/platform.c     | 5 -----
 drivers/spi/spi.c         | 5 -----
 5 files changed, 22 deletions(-)

diff --git a/drivers/bus/imx-weim.c b/drivers/bus/imx-weim.c
index 837bf9d51c6e..caaf887e0ccc 100644
--- a/drivers/bus/imx-weim.c
+++ b/drivers/bus/imx-weim.c
@@ -331,12 +331,6 @@ static int of_weim_notify(struct notifier_block *nb, unsigned long action,
 				 "Failed to setup timing for '%pOF'\n", rd->dn);
 
 		if (!of_node_check_flag(rd->dn, OF_POPULATED)) {
-			/*
-			 * Clear the flag before adding the device so that
-			 * fw_devlink doesn't skip adding consumers to this
-			 * device.
-			 */
-			rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
 			if (!of_platform_device_create(rd->dn, NULL, &pdev->dev)) {
 				dev_err(&pdev->dev,
 					"Failed to create child device '%pOF'\n",
diff --git a/drivers/i2c/i2c-core-of.c b/drivers/i2c/i2c-core-of.c
index a6c407d36800..a250921bbce0 100644
--- a/drivers/i2c/i2c-core-of.c
+++ b/drivers/i2c/i2c-core-of.c
@@ -178,11 +178,6 @@ static int of_i2c_notify(struct notifier_block *nb, unsigned long action,
 			return NOTIFY_OK;
 		}
 
-		/*
-		 * Clear the flag before adding the device so that fw_devlink
-		 * doesn't skip adding consumers to this device.
-		 */
-		rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
 		client = of_i2c_register_device(adap, rd->dn);
 		if (IS_ERR(client)) {
 			dev_err(&adap->dev, "failed to create client for '%pOF'\n",
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index 4d57a4e34105..19a1a38554f2 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -224,7 +224,6 @@ static void __of_attach_node(struct device_node *np)
 	np->sibling = np->parent->child;
 	np->parent->child = np;
 	of_node_clear_flag(np, OF_DETACHED);
-	np->fwnode.flags |= FWNODE_FLAG_NOT_DEVICE;
 
 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
 
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 389d4ea6bfc1..efd861fa254f 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -743,11 +743,6 @@ static int of_platform_notify(struct notifier_block *nb,
 		if (of_node_check_flag(rd->dn, OF_POPULATED))
 			return NOTIFY_OK;
 
-		/*
-		 * Clear the flag before adding the device so that fw_devlink
-		 * doesn't skip adding consumers to this device.
-		 */
-		rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
 		/* pdev_parent may be NULL when no bus platform device */
 		pdev_parent = of_find_device_by_node(rd->dn->parent);
 		pdev = of_platform_device_create(rd->dn, NULL,
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index ff75838c1b5d..17cd417f7681 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -4761,11 +4761,6 @@ static int of_spi_notify(struct notifier_block *nb, unsigned long action,
 			return NOTIFY_OK;
 		}
 
-		/*
-		 * Clear the flag before adding the device so that fw_devlink
-		 * doesn't skip adding consumers to this device.
-		 */
-		rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
 		spi = of_register_spi_device(ctlr, rd->dn);
 		put_device(&ctlr->dev);
 
-- 
2.44.0.478.gd926399ef9-goog

[RFC PATCH v1 2/2] of: dynamic: Fix probing of overlay devices

[Saravana Kannan]

Get fw_devlink to work well with overlay devices.

Signed-off-by: Saravana Kannan <saravanak@google.com>
---
 drivers/base/core.c    | 10 ++++++++++
 drivers/of/dynamic.c   |  8 ++++++++
 include/linux/fwnode.h |  2 ++
 3 files changed, 20 insertions(+)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 5f4e03336e68..d856f9c5d601 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -237,6 +237,16 @@ static void __fw_devlink_pickup_dangling_consumers(struct fwnode_handle *fwnode,
 		__fw_devlink_pickup_dangling_consumers(child, new_sup);
 }
 
+
+void fw_devlink_pickup_dangling_consumers(struct fwnode_handle *child,
+						 struct fwnode_handle *parent)
+{
+	mutex_lock(&fwnode_link_lock);
+	__fw_devlink_pickup_dangling_consumers(child, parent);
+	__fw_devlink_link_to_consumers(parent->dev);
+	mutex_unlock(&fwnode_link_lock);
+}
+
 static DEFINE_MUTEX(device_links_lock);
 DEFINE_STATIC_SRCU(device_links_srcu);
 
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index 19a1a38554f2..0a936f46820e 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -237,6 +237,7 @@ static void __of_attach_node(struct device_node *np)
 int of_attach_node(struct device_node *np)
 {
 	struct of_reconfig_data rd;
+	struct fwnode_handle *fwnode, *parent;
 
 	memset(&rd, 0, sizeof(rd));
 	rd.dn = np;
@@ -246,6 +247,13 @@ int of_attach_node(struct device_node *np)
 	mutex_unlock(&of_mutex);
 
 	of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, &rd);
+	fwnode = of_fwnode_handle(np);
+	fwnode_for_each_parent_node(fwnode, parent)
+		if (parent->dev) {
+			fw_devlink_pickup_dangling_consumers(fwnode, parent);
+			fwnode_handle_put(parent);
+			break;
+		}
 
 	return 0;
 }
diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h
index 0d79070c5a70..4b3f697a90e8 100644
--- a/include/linux/fwnode.h
+++ b/include/linux/fwnode.h
@@ -220,6 +220,8 @@ int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup,
 		    u8 flags);
 void fwnode_links_purge(struct fwnode_handle *fwnode);
 void fw_devlink_purge_absent_suppliers(struct fwnode_handle *fwnode);
+void fw_devlink_pickup_dangling_consumers(struct fwnode_handle *child,
+					  struct fwnode_handle *parent);
 bool fw_devlink_is_strict(void);
 
 #endif
-- 
2.44.0.478.gd926399ef9-goog

Re: [RFC PATCH v1 2/2] of: dynamic: Fix probing of overlay devices

[Saravana Kannan]

On Mon, Apr 8, 2024 at 4:13 PM Saravana Kannan <saravanak@google.com> wrote:
>
> Get fw_devlink to work well with overlay devices.
>
> Signed-off-by: Saravana Kannan <saravanak@google.com>
> ---
>  drivers/base/core.c    | 10 ++++++++++
>  drivers/of/dynamic.c   |  8 ++++++++
>  include/linux/fwnode.h |  2 ++
>  3 files changed, 20 insertions(+)
>
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index 5f4e03336e68..d856f9c5d601 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -237,6 +237,16 @@ static void __fw_devlink_pickup_dangling_consumers(struct fwnode_handle *fwnode,
>                 __fw_devlink_pickup_dangling_consumers(child, new_sup);
>  }
>
> +
> +void fw_devlink_pickup_dangling_consumers(struct fwnode_handle *child,
> +                                                struct fwnode_handle *parent)
> +{
> +       mutex_lock(&fwnode_link_lock);
> +       __fw_devlink_pickup_dangling_consumers(child, parent);
> +       __fw_devlink_link_to_consumers(parent->dev);
> +       mutex_unlock(&fwnode_link_lock);
> +}
> +
>  static DEFINE_MUTEX(device_links_lock);
>  DEFINE_STATIC_SRCU(device_links_srcu);
>
> diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
> index 19a1a38554f2..0a936f46820e 100644
> --- a/drivers/of/dynamic.c
> +++ b/drivers/of/dynamic.c
> @@ -237,6 +237,7 @@ static void __of_attach_node(struct device_node *np)
>  int of_attach_node(struct device_node *np)
>  {
>         struct of_reconfig_data rd;
> +       struct fwnode_handle *fwnode, *parent;
>
>         memset(&rd, 0, sizeof(rd));
>         rd.dn = np;
> @@ -246,6 +247,13 @@ int of_attach_node(struct device_node *np)
>         mutex_unlock(&of_mutex);
>
>         of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, &rd);
> +       fwnode = of_fwnode_handle(np);
> +       fwnode_for_each_parent_node(fwnode, parent)
> +               if (parent->dev) {
> +                       fw_devlink_pickup_dangling_consumers(fwnode, parent);
> +                       fwnode_handle_put(parent);
> +                       break;
> +               }

I'm clearly calling this in the wrong location. Please move this logic
to __of_changeset_entry_notify() and for the case
OF_RECONFIG_ATTACH_NODE. Haven't fully thought through the DETACH
case, but it should work correctly for that case too. If not, I'll
take care of that next.

-Saravana

>
>         return 0;
>  }
> diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h
> index 0d79070c5a70..4b3f697a90e8 100644
> --- a/include/linux/fwnode.h
> +++ b/include/linux/fwnode.h
> @@ -220,6 +220,8 @@ int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup,
>                     u8 flags);
>  void fwnode_links_purge(struct fwnode_handle *fwnode);
>  void fw_devlink_purge_absent_suppliers(struct fwnode_handle *fwnode);
> +void fw_devlink_pickup_dangling_consumers(struct fwnode_handle *child,
> +                                         struct fwnode_handle *parent);
>  bool fw_devlink_is_strict(void);
>
>  #endif
> --
> 2.44.0.478.gd926399ef9-goog
>

Re: [RFC PATCH v1 2/2] of: dynamic: Fix probing of overlay devices

[Saravana Kannan]

On Mon, Apr 8, 2024 at 6:40 PM Saravana Kannan <saravanak@google.com> wrote:
>
> On Mon, Apr 8, 2024 at 4:13 PM Saravana Kannan <saravanak@google.com> wrote:
> >
> > Get fw_devlink to work well with overlay devices.
> >
> > Signed-off-by: Saravana Kannan <saravanak@google.com>
> > ---
> >  drivers/base/core.c    | 10 ++++++++++
> >  drivers/of/dynamic.c   |  8 ++++++++
> >  include/linux/fwnode.h |  2 ++
> >  3 files changed, 20 insertions(+)
> >
> > diff --git a/drivers/base/core.c b/drivers/base/core.c
> > index 5f4e03336e68..d856f9c5d601 100644
> > --- a/drivers/base/core.c
> > +++ b/drivers/base/core.c
> > @@ -237,6 +237,16 @@ static void __fw_devlink_pickup_dangling_consumers(struct fwnode_handle *fwnode,
> >                 __fw_devlink_pickup_dangling_consumers(child, new_sup);
> >  }
> >
> > +
> > +void fw_devlink_pickup_dangling_consumers(struct fwnode_handle *child,
> > +                                                struct fwnode_handle *parent)
> > +{
> > +       mutex_lock(&fwnode_link_lock);
> > +       __fw_devlink_pickup_dangling_consumers(child, parent);
> > +       __fw_devlink_link_to_consumers(parent->dev);
> > +       mutex_unlock(&fwnode_link_lock);
> > +}
> > +
> >  static DEFINE_MUTEX(device_links_lock);
> >  DEFINE_STATIC_SRCU(device_links_srcu);
> >
> > diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
> > index 19a1a38554f2..0a936f46820e 100644
> > --- a/drivers/of/dynamic.c
> > +++ b/drivers/of/dynamic.c
> > @@ -237,6 +237,7 @@ static void __of_attach_node(struct device_node *np)
> >  int of_attach_node(struct device_node *np)
> >  {
> >         struct of_reconfig_data rd;
> > +       struct fwnode_handle *fwnode, *parent;
> >
> >         memset(&rd, 0, sizeof(rd));
> >         rd.dn = np;
> > @@ -246,6 +247,13 @@ int of_attach_node(struct device_node *np)
> >         mutex_unlock(&of_mutex);
> >
> >         of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, &rd);
> > +       fwnode = of_fwnode_handle(np);
> > +       fwnode_for_each_parent_node(fwnode, parent)
> > +               if (parent->dev) {
> > +                       fw_devlink_pickup_dangling_consumers(fwnode, parent);
> > +                       fwnode_handle_put(parent);
> > +                       break;
> > +               }
>
> I'm clearly calling this in the wrong location. Please move this logic
> to __of_changeset_entry_notify() and for the case
> OF_RECONFIG_ATTACH_NODE. Haven't fully thought through the DETACH
> case, but it should work correctly for that case too. If not, I'll
> take care of that next.
>

I'll send out a RFC v2 with the code fixed up in a few minutes.

> -Saravana
>
> >
> >         return 0;
> >  }
> > diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h
> > index 0d79070c5a70..4b3f697a90e8 100644
> > --- a/include/linux/fwnode.h
> > +++ b/include/linux/fwnode.h
> > @@ -220,6 +220,8 @@ int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup,
> >                     u8 flags);
> >  void fwnode_links_purge(struct fwnode_handle *fwnode);
> >  void fw_devlink_purge_absent_suppliers(struct fwnode_handle *fwnode);
> > +void fw_devlink_pickup_dangling_consumers(struct fwnode_handle *child,
> > +                                         struct fwnode_handle *parent);
> >  bool fw_devlink_is_strict(void);
> >
> >  #endif
> > --
> > 2.44.0.478.gd926399ef9-goog
> >