Re: [PATCH] of: Fix cpu node iterator to not ignore disabled cpu nodes

From: Michael Ellerman
Date: Thu Nov 01 2018 - 07:08:52 EST


Rob Herring <robh@xxxxxxxxxx> writes:

> In most cases, nodes with 'status = "disabled";' are treated as if the
> node is not present though it is a common bug to forget to check that.
> However, cpu nodes are different in that "disabled" simply means offline
> and the OS can bring the CPU core online. Commit f1f207e43b8a ("of: Add
> cpu node iterator for_each_of_cpu_node()") followed the common behavior
> of ignoring disabled cpu nodes. This breaks some powerpc systems (at
> least NXP P50XX/e5500). Fix this by dropping the status check.
>
> Fixes: 651d44f9679c ("of: use for_each_of_cpu_node iterator")
> Fixes: f1f207e43b8a ("of: Add cpu node iterator for_each_of_cpu_node()")
> Reported-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> Cc: Christian Zigotzky <chzigotzky@xxxxxxxxxxx>
> Cc: Frank Rowand <frowand.list@xxxxxxxxx>
> Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
> ---
> drivers/of/base.c | 2 --
> 1 file changed, 2 deletions(-)

This fixes my machine, thanks.

Tested-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>

It was actually originally reported to me by Christian, so also:

Reported-by: Christian Zigotzky <chzigotzky@xxxxxxxxxxx>


cheers

> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index cc62da278663..e47c5ce6cd58 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -776,8 +776,6 @@ struct device_node *of_get_next_cpu_node(struct device_node *prev)
> if (!(of_node_name_eq(next, "cpu") ||
> (next->type && !of_node_cmp(next->type, "cpu"))))
> continue;
> - if (!__of_device_is_available(next))
> - continue;
> if (of_node_get(next))
> break;
> }
> --
> 2.19.1