Re: [PATCH] coresight: etm4x: Fix missing trctraceidr file in sysfs

[Suzuki K Poulose <suzuki.poulose@arm.com>]

On 12/05/2023 14:30, Mike Leach wrote:
> The trace ID patchset adjusted the handling of the TRCTRACEIDR register
> sysfs to allocate on read.
> 
> Although this was initally correct, the final version of the patch series
> introduced an error which resulted in the mgmt/trctraceidr file in sysfs
> not being visible.
> 
> This patch fixes that issue.
> 
> Fixes: df4871204e5d ("coresight: etm4x: Update ETM4 driver to use Trace ID API")
> 
> Reported-by: Junhao He <hejunhao3@huawei.com>
> Link: https://lists.linaro.org/archives/list/coresight@lists.linaro.org/thread/KK3CVVMRHJWVUORKMFJRSXYCEDFKENQJ/
> 
> Signed-off-by: Mike Leach <mike.leach@linaro.org>
> ---
>   .../coresight/coresight-etm4x-sysfs.c         | 27 ++++++++++++-------
>   1 file changed, 18 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> index 5e62aa40ecd0..a9f19629f3f8 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> @@ -2411,7 +2411,6 @@ static ssize_t trctraceid_show(struct device *dev,
>   
>   	return sysfs_emit(buf, "0x%x\n", trace_id);
>   }
> -static DEVICE_ATTR_RO(trctraceid);
>   
>   struct etmv4_reg {
>   	struct coresight_device *csdev;
> @@ -2528,13 +2527,23 @@ coresight_etm4x_attr_reg_implemented(struct kobject *kobj,
>   	return 0;
>   }
>   
> -#define coresight_etm4x_reg(name, offset)				\
> -	&((struct dev_ext_attribute[]) {				\
> -	   {								\
> -		__ATTR(name, 0444, coresight_etm4x_reg_show, NULL),	\
> -		(void *)(unsigned long)offset				\
> -	   }								\
> -	})[0].attr.attr
> +/*
> + * Macro to set an RO ext attribute with offset and show function.
> + * Offset is used in mgmt group to ensure only correct registers for
> + * the ETM / ETE variant are visible.
> + */
> +#define coresight_etm4x_reg_showfn(name, offset, showfn) (	\
> +	&((struct dev_ext_attribute[]) {			\
> +	   {							\
> +		__ATTR(name, 0444, showfn, NULL),		\
> +		(void *)(unsigned long)offset			\
> +	   }							\
> +	})[0].attr.attr						\
> +	)
> +
> +/* macro using the default coresight_etm4x_reg_show function */
> +#define coresight_etm4x_reg(name, offset)	\
> +	coresight_etm4x_reg_showfn(name, offset, coresight_etm4x_reg_show)
>   
>   static struct attribute *coresight_etmv4_mgmt_attrs[] = {
>   	coresight_etm4x_reg(trcpdcr, TRCPDCR),
> @@ -2549,7 +2558,7 @@ static struct attribute *coresight_etmv4_mgmt_attrs[] = {
>   	coresight_etm4x_reg(trcpidr3, TRCPIDR3),
>   	coresight_etm4x_reg(trcoslsr, TRCOSLSR),
>   	coresight_etm4x_reg(trcconfig, TRCCONFIGR),
> -	&dev_attr_trctraceid.attr,
> +	coresight_etm4x_reg_showfn(trctraceid, TRCTRACEIDR, trctraceid_show),
>   	coresight_etm4x_reg(trcdevarch, TRCDEVARCH),
>   	NULL,
>   };


Looks good to me, Thanks for the fix. I will queue this.

Suzuki