On Tue, 18 Nov 2025 at 16:28, James Clark <james.clark@linaro.org> wrote:
>
> ETMv3 only has a few attributes, and setting unused ones results in an
> error, so hide them to begin with.
>
> Signed-off-by: James Clark <james.clark@linaro.org>
> ---
> drivers/hwtracing/coresight/coresight-etm-perf.c | 22 ++++++++++++++++++++++
> 1 file changed, 22 insertions(+)
>
> diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
> index 17afa0f4cdee..faebd7822a77 100644
> --- a/drivers/hwtracing/coresight/coresight-etm-perf.c
> +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
> @@ -106,8 +106,30 @@ static struct attribute *etm_config_formats_attr[] = {
> NULL,
> };
>
> +static umode_t etm_format_attr_is_visible(struct kobject *kobj,
> + struct attribute *attr, int unused)
> +{
> + /* ETM4 has all attributes */
> + if (IS_ENABLED(CONFIG_CORESIGHT_SOURCE_ETM4X))
> + return attr->mode;
> +
> + /*
> + * ETM3 only uses these attributes for programming itself (see
> + * ETM3X_SUPPORTED_OPTIONS). Sink ID is also supported for selecting a
> + * sink, but not used for configuring the ETM.
> + */
> + if (attr == &format_attr_cycacc.attr ||
> + attr == &format_attr_timestamp.attr ||
> + attr == &format_attr_retstack.attr ||
> + attr == &format_attr_sinkid.attr)
> + return attr->mode;
> +
> + return 0;
> +}
> +
> static const struct attribute_group etm_pmu_format_group = {
> .name = "format",
> + .is_visible = etm_format_attr_is_visible,
> .attrs = etm_config_formats_attr,
> };
>
>
> --
> 2.34.1
>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
--
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK