[PATCH] base: fix order of OF initialization

[PATCH] base: fix order of OF initialization

[Christoph Hellwig]

From: "Wesley W. Terpstra" <wesley@sifive.com>

This fixes: [    0.010000] cpu cpu0: Error -2 creating of_node link
... which you get for every CPU on all architectures that use
CONFIG_GENERIC_CPU_DEVICES.

In that case, driver_init() calls cpu_dev_init() before calling
of_core_init(). Then we get the callchain:

  cpu_dev_init()
    -> cpu_dev_register_generic()
    -> register_cpu(cpu, i)
    -> device_register(&cpu->dev)
    -> device_add(dev)
    -> device_add_class_symlinks(dev)

... in device_add_class_symlinks, we we dev->of_node, and call
sysfs_create_link(), which fails because we haven't called
of_core_init() to register the sysfs devicetree directory yet.

Signed-off-by: Wesley W. Terpstra <wesley@sifive.com>
[hch: updated the changelog based on review feedback]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Frank Rowand <frowand.list@gmail.com>
---

In case anyone is wondering why I send out this patch - I'm digging
through the RISC-V tree and trying to the patches required to let
a RISC-V kernel boot on qemu upstream.  I also got the previously
missing signoff from Wes offlist.

 drivers/base/init.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/base/init.c b/drivers/base/init.c
index dd85b05a6a16..908e6520e804 100644
--- a/drivers/base/init.c
+++ b/drivers/base/init.c
@@ -30,9 +30,9 @@ void __init driver_init(void)
 	/* These are also core pieces, but must come after the
 	 * core core pieces.
 	 */
+	of_core_init();
 	platform_bus_init();
 	cpu_dev_init();
 	memory_dev_init();
 	container_dev_init();
-	of_core_init();
 }
-- 
2.17.1

Re: [PATCH] base: fix order of OF initialization

[Frank Rowand]

On 06/21/18 06:37, Christoph Hellwig wrote:
> From: "Wesley W. Terpstra" <wesley@sifive.com>
> 
> This fixes: [    0.010000] cpu cpu0: Error -2 creating of_node link
> ... which you get for every CPU on all architectures that use
> CONFIG_GENERIC_CPU_DEVICES.
> 
> In that case, driver_init() calls cpu_dev_init() before calling
> of_core_init(). Then we get the callchain:
> 
>   cpu_dev_init()
>     -> cpu_dev_register_generic()
>     -> register_cpu(cpu, i)
>     -> device_register(&cpu->dev)
>     -> device_add(dev)
>     -> device_add_class_symlinks(dev)
> 
> ... in device_add_class_symlinks, we we dev->of_node, and call
> sysfs_create_link(), which fails because we haven't called
> of_core_init() to register the sysfs devicetree directory yet.
> 
> Signed-off-by: Wesley W. Terpstra <wesley@sifive.com>
> [hch: updated the changelog based on review feedback]
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Acked-by: Mark Rutland <mark.rutland@arm.com>
> Acked-by: Frank Rowand <frowand.list@gmail.com>
> ---
> 
> In case anyone is wondering why I send out this patch - I'm digging
> through the RISC-V tree and trying to the patches required to let
> a RISC-V kernel boot on qemu upstream.  I also got the previously
> missing signoff from Wes offlist.
> 
>  drivers/base/init.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/base/init.c b/drivers/base/init.c
> index dd85b05a6a16..908e6520e804 100644
> --- a/drivers/base/init.c
> +++ b/drivers/base/init.c
> @@ -30,9 +30,9 @@ void __init driver_init(void)
>  	/* These are also core pieces, but must come after the
>  	 * core core pieces.
>  	 */
> +	of_core_init();
>  	platform_bus_init();
>  	cpu_dev_init();
>  	memory_dev_init();
>  	container_dev_init();
> -	of_core_init();
>  }
> 

The updated patch comment looks good.  It would be good to get this into
-next while we are still early in the release cycle.

For those trying to find the previous version of this patch, it was cced
to the devicetree list on 06/07/17.

-Frank