Re: [PATCH v2] treewide: Fix instantiation of devices in DT overlays

From: Frank Rowand
Date: Wed Mar 29 2023 - 12:08:20 EST


On 3/24/23 04:30, Geert Uytterhoeven wrote:
> When loading a DT overlay that creates a device, the device is not
> instantiated, unless the DT overlay is unloaded and reloaded again.

Can you elaborate on why this is? What the relevant code paths are?

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


>
> Fixes: 4a032827daa89350 ("of: property: Simplify of_link_to_phandle()")

>From a quick scan of the fixed commit, I don't see how that commit caused the problem.
Can you give a quick clue? (The clue does not need to be added to the commit message,
but please at least put it below the "---" if there are additional versions of this
patch.)

> Link: https://lore.kernel.org/r/CAGETcx_+rhHvaC_HJXGrr5_WAd2+k5f=rWYnkCZ6z5bGX-wj4w@xxxxxxxxxxxxxx
> Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> Acked-by: Mark Brown <broonie@xxxxxxxxxx>
> ---
> v2:
> - Add Acked-by,
> - Drop RFC.
> ---
> 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 36d42484142aede2..898e23a4231400fa 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 aa93467784c29c89..303f9003562eed3d 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 8e8af148b1dc371e..66ac67580d2a473b 100644
> --- a/drivers/spi/spi.c
> +++ b/drivers/spi/spi.c
> @@ -4527,6 +4527,7 @@ 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);
>