Re: [PATCH 1/2] coresight: Set affinity to invalid for missing CPU phandle

From: Mathieu Poirier
Date: Thu Jun 20 2019 - 13:39:14 EST


Hi Sai,

On Thu, Jun 20, 2019 at 07:15:46PM +0530, Sai Prakash Ranjan wrote:
> Affinity defaults to CPU0 in case of missing CPU phandle
> and this leads to crashes in some cases because of such
> wrong assumption. Fix this by returning -ENODEV in
> coresight platform for such cases and then handle it
> in the coresight drivers.
>
> Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@xxxxxxxxxxxxxx>
> ---
> drivers/hwtracing/coresight/coresight-platform.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-platform.c b/drivers/hwtracing/coresight/coresight-platform.c
> index 3c5ceda8db24..b1ea60c210e1 100644
> --- a/drivers/hwtracing/coresight/coresight-platform.c
> +++ b/drivers/hwtracing/coresight/coresight-platform.c
> @@ -160,15 +160,17 @@ static int of_coresight_get_cpu(struct device *dev)
>
> if (!dev->of_node)
> return 0;

An error should be returned if the above condition is true.

> +

Spurious newline

> dn = of_parse_phandle(dev->of_node, "cpu", 0);
> - /* Affinity defaults to CPU0 */
> +
> + /* Affinity defaults to invalid if no cpu nodes are found*/
> if (!dn)
> - return 0;
> + return -ENODEV;
> +
> cpu = of_cpu_node_to_id(dn);
> of_node_put(dn);
>
> - /* Affinity to CPU0 if no cpu nodes are found */
> - return (cpu < 0) ? 0 : cpu;
> + return cpu;
> }
>
> /*
> --
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