linux-kernel - [PATCH/RFC] treewide: Fix instantiation of devices in DT overlay

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Message-Id: <328e557aaee9d3f5f1bcaf2b8ac2de0e04c4fbb8.1679049188.git.geert+renesas@glider.be>
Date:   Fri, 17 Mar 2023 11:33:18 +0100
From:   Geert Uytterhoeven <geert+renesas@...der.be>
To:     Saravana Kannan <saravanak@...gle.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     Shawn Guo <shawnguo@...nel.org>,
        Sascha Hauer <s.hauer@...gutronix.de>,
        Pengutronix Kernel Team <kernel@...gutronix.de>,
        Fabio Estevam <festevam@...il.com>,
        NXP Linux Team <linux-imx@....com>,
        Wolfram Sang <wsa@...nel.org>,
        Rob Herring <robh+dt@...nel.org>,
        Frank Rowand <frowand.list@...il.com>,
        Mark Brown <broonie@...nel.org>,
        linux-arm-kernel@...ts.infradead.org, linux-i2c@...r.kernel.org,
        devicetree@...r.kernel.org, linux-spi@...r.kernel.org,
        linux-renesas-soc@...r.kernel.org, linux-kernel@...r.kernel.org,
        Geert Uytterhoeven <geert+renesas@...der.be>
Subject: [PATCH/RFC] treewide: Fix instantiation of devices in DT overlay

When loading a DT overlay that creates a device, the device is not
instantiated, unless the DT overlay is unloaded and reloaded again.

Saravana explains:
  Basically for all overlays (I hope the function is only used for
  overlays) we assume all nodes are NOT devices until they actually
  get added as a device. Don't review the code, it's not meant to be :)

Based on a hacky patch by Saravana Kannan, which covered only platform
and spi devices.

Fixes: 4a032827daa89350 ("of: property: Simplify of_link_to_phandle()")
Link: https://lore.kernel.org/all/CAGETcx_+rhHvaC_HJXGrr5_WAd2+k5f=rWYnkCZ6z5bGX-wj4w@mail.gmail.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@...der.be>
---
Marked RFC as Saravana said this is an ugly hack.
Still, this is a regression in v6.3-rc1 that should be fixed.
---
 drivers/bus/imx-weim.c    | 1 +
 drivers/i2c/i2c-core-of.c | 1 +
 drivers/of/dynamic.c      | 1 +
 drivers/of/platform.c     | 1 +
 drivers/spi/spi.c         | 1 +
 5 files changed, 5 insertions(+)

diff --git a/drivers/bus/imx-weim.c b/drivers/bus/imx-weim.c
index 2a6b4f676458612e..71d8807170fa9f29 100644
--- a/drivers/bus/imx-weim.c
+++ b/drivers/bus/imx-weim.c
@@ -329,6 +329,7 @@ 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)) {
+			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 bce6b796e04c2ca0..79a0d47010ba0b20 100644
--- a/drivers/i2c/i2c-core-of.c
+++ b/drivers/i2c/i2c-core-of.c
@@ -178,6 +178,7 @@ static int of_i2c_notify(struct notifier_block *nb, unsigned long action,
 			return NOTIFY_OK;
 		}
 
+		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 07d93753b12f5f4d..e311d406b1705306 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -226,6 +226,7 @@ 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;
 }
 
 /**
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index b2bd2e783445dd78..17c92cbfb62ee3ef 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -737,6 +737,7 @@ static int of_platform_notify(struct notifier_block *nb,
 		if (of_node_check_flag(rd->dn, OF_POPULATED))
 			return NOTIFY_OK;
 
+		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 1a65f96fe2aff591..7bd053a32fad1a3c 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -4480,6 +4480,7 @@ static int of_spi_notify(struct notifier_block *nb, unsigned long action,
 			return NOTIFY_OK;
 		}
 
+		rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
 		spi = of_register_spi_device(ctlr, rd->dn);
 		put_device(&ctlr->dev);
 
-- 
2.34.1