Re: [PATCH 05/13] coresight: etm3: Add support for handling errors

[Mathieu Poirier]

On Mon, Aug 06, 2018 at 02:41:47PM +0100, Suzuki K Poulose wrote:
> Add support for reporting errors back from the SMP cross
> function call for enabling ETM.
> 
> Cc: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
> ---
>  drivers/hwtracing/coresight/coresight-etm3x.c | 42 ++++++++++++++++++---------
>  1 file changed, 28 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/hwtracing/coresight/coresight-etm3x.c b/drivers/hwtracing/coresight/coresight-etm3x.c
> index 9ce8fba..771691c 100644
> --- a/drivers/hwtracing/coresight/coresight-etm3x.c
> +++ b/drivers/hwtracing/coresight/coresight-etm3x.c
> @@ -355,11 +355,10 @@ static int etm_parse_event_config(struct etm_drvdata *drvdata,
>  	return 0;
>  }
>  
> -static void etm_enable_hw(void *info)
> +static int etm_enable_hw(struct etm_drvdata *drvdata)
>  {
>  	int i;
>  	u32 etmcr;
> -	struct etm_drvdata *drvdata = info;
>  	struct etm_config *config = &drvdata->config;
>  
>  	CS_UNLOCK(drvdata->base);
> @@ -421,6 +420,21 @@ static void etm_enable_hw(void *info)
>  	CS_LOCK(drvdata->base);
>  
>  	dev_dbg(drvdata->dev, "cpu: %d enable smp call done\n", drvdata->cpu);
> +	return 0;
> +}
> +
> +struct etm_enable_arg {
> +	struct etm_drvdata *drvdata;
> +	int rc;
> +}

This doesn't compile a ';' is missing.

> +
> +static void etm_enable_hw_smp_call(void *info)
> +{
> +	struct etm_enable_arg *arg = info;
> +
> +	if (WARN_ON(!arg))
> +		return;
> +	arg->rc = etm_enable_hw(arg->drvdata);
>  }
>  
>  static int etm_cpu_id(struct coresight_device *csdev)
> @@ -475,14 +489,13 @@ static int etm_enable_perf(struct coresight_device *csdev,
>  	/* Configure the tracer based on the session's specifics */
>  	etm_parse_event_config(drvdata, event);
>  	/* And enable it */
> -	etm_enable_hw(drvdata);
> -
> -	return 0;
> +	return etm_enable_hw(drvdata);
>  }
>  
>  static int etm_enable_sysfs(struct coresight_device *csdev)
>  {
>  	struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
> +	struct etm_enable_arg arg = { 0 };
>  	int ret;
>  
>  	spin_lock(&drvdata->spinlock);
> @@ -492,20 +505,21 @@ static int etm_enable_sysfs(struct coresight_device *csdev)
>  	 * hw configuration will take place on the local CPU during bring up.
>  	 */
>  	if (cpu_online(drvdata->cpu)) {
> +		arg.drvdata = drvdata;
>  		ret = smp_call_function_single(drvdata->cpu,
> -					       etm_enable_hw, drvdata, 1);
> -		if (ret)
> -			goto err;
> +					       etm_enable_hw_smp_call, &arg, 1);
> +		if (!ret)
> +			ret = arg.rc;
> +		if (!ret)
> +			drvdata->sticky_enable = true;
> +	} else {
> +		ret = -ENODEV;
>  	}
>  
> -	drvdata->sticky_enable = true;
>  	spin_unlock(&drvdata->spinlock);
>  
> -	dev_dbg(drvdata->dev, "ETM tracing enabled\n");
> -	return 0;
> -
> -err:
> -	spin_unlock(&drvdata->spinlock);
> +	if (!ret)
> +		dev_dbg(drvdata->dev, "ETM tracing enabled\n");
>  	return ret;
>  }
>  
> -- 
> 2.7.4
>