treewide: Fix probing of devices in DT overlays

commit 1a50d9403fb90cbe4dea0ec9fd0351d2ecbd8924 upstream.

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

After the recent refactoring to improve fw_devlink, it no longer depends
on the "compatible" property to identify which device tree nodes will
become struct devices.   fw_devlink now picks up dangling consumers
(consumers pointing to descendent device tree nodes of a device that
aren't converted to child devices) when a device is successfully bound
to a driver.  See __fw_devlink_pickup_dangling_consumers().

However, during DT overlay, a device's device tree node can have
sub-nodes added/removed without unbinding/rebinding the driver.  This
difference in behavior between the normal device instantiation and
probing flow vs. the DT overlay flow has a bunch of implications that
are pointed out elsewhere[1].  One of them is that the fw_devlink logic
to pick up dangling consumers is never exercised.

This patch solves the fw_devlink issue by marking all DT nodes added by
DT overlays with FWNODE_FLAG_NOT_DEVICE (fwnode that won't become
device), and by clearing the flag when a struct device is actually
created for the DT node.  This way, fw_devlink knows not to have
consumers waiting on these newly added DT nodes, and to propagate the
dependency to an ancestor DT node that has the corresponding struct
device.

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

[1] https://lore.kernel.org/r/CAGETcx_bkuFaLCiPrAWCPQz+w79ccDp6=9e881qmK=vx3hBMyg@mail.gmail.com

Fixes: 4a032827daa89350 ("of: property: Simplify of_link_to_phandle()")
Link: https://lore.kernel.org/r/CAGETcx_+rhHvaC_HJXGrr5_WAd2+k5f=rWYnkCZ6z5bGX-wj4w@mail.gmail.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C
Acked-by: Shawn Guo <shawnguo@kernel.org>
Acked-by: Saravana Kannan <saravanak@google.com>
Tested-by: Ivan Bornyakov <i.bornyakov@metrotek.ru>
Link: https://lore.kernel.org/r/e1fa546682ea4c8474ff997ab6244c5e11b6f8bc.1680182615.git.geert+renesas@glider.be
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/bus/imx-weim.c b/drivers/bus/imx-weim.c
index 55d917bd1f3f8f57c56452aaa97628d12720568e..64f9eacd1b38dc63a2c3c09b5483ee1c57c7eaae 100644 (file)
--- a/drivers/bus/imx-weim.c
+++ b/drivers/bus/imx-weim.c
@@ -331,6 +331,12 @@ 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 3ed74aa4b44bb835a9296945af14ca1b98f30ea8..1073f82d5dd47fc36dc4a34999cc5989d988b67a 100644 (file)
--- a/drivers/i2c/i2c-core-of.c
+++ b/drivers/i2c/i2c-core-of.c
@@ -244,6 +244,11 @@ 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 4e436f2d13aeb64e91199ae0345d5a8f1dc225c0..95501b77ef3146dbf1d68c9c75b36f2d28697fb6 100644 (file)
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -225,6 +225,7 @@ 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 e181c3f50f1da7e743169cf440e86e435d1a5c33..bf96862cb7003ba87720441edca2fb3712f17f50 100644 (file)
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -741,6 +741,11 @@ 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 5f9aedd1f0b65e4f356c1a2a466196efd91c4a29..151fef199c3805c41c6a0cd112eeae6094cfa92d 100644 (file)
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -4370,6 +4370,11 @@ 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);