On 2023-04-04 at 15:31:02 +0200, alexis.lothore@xxxxxxxxxxx wrote:
> From: Alexis Lothoré <alexis.lothore@xxxxxxxxxxx>
>
> The current code path can lead to warnings because of uninitialized device,
> which contains, as a consequence, uninitialized kobject. The uninitialized
> device is passed to of_platform_populate, which will at some point, while
> creating child device, try to get a reference on uninitialized parent,
> resulting in the following warning:
>
> kobject: '(null)' ((ptrval)): is not initialized, yet kobject_get() is
> being called.
>
> The warning is observed after migrating a kernel 5.10.x to 6.1.x.
> Reverting commit 0d70af3c2530 ("fpga: bridge: Use standard dev_release for
> class driver") seems to remove the warning.
> This commit aggregates device_initialize() and device_add() into
> device_register() but this new call is done AFTER of_platform_populate
>
> Fixes: 0d70af3c2530 ("fpga: bridge: Use standard dev_release for class driver")
> Signed-off-by: Alexis Lothoré <alexis.lothore@xxxxxxxxxxx>
> ---
> drivers/fpga/fpga-bridge.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/fpga/fpga-bridge.c b/drivers/fpga/fpga-bridge.c
> index 727704431f61..13918c8c839e 100644
> --- a/drivers/fpga/fpga-bridge.c
> +++ b/drivers/fpga/fpga-bridge.c
> @@ -360,7 +360,6 @@ fpga_bridge_register(struct device *parent, const char *name,
> bridge->dev.parent = parent;
> bridge->dev.of_node = parent->of_node;
> bridge->dev.id = id;
> - of_platform_populate(bridge->dev.of_node, NULL, NULL, &bridge->dev);
>
> ret = dev_set_name(&bridge->dev, "br%d", id);
> if (ret)
> @@ -372,6 +371,8 @@ fpga_bridge_register(struct device *parent, const char *name,
> return ERR_PTR(ret);
> }
>
> + of_platform_populate(bridge->dev.of_node, NULL, NULL, &bridge->dev);
It makes sense.
Acked-by: Xu Yilun <yilun.xu@xxxxxxxxx>
Applied
> +
> return bridge;
>
> error_device:
> --
> 2.40.0
>
