Re: [PATCH] coresight: Handle build path error

Mathieu Poirier
2016-05-06T14:26:42Z

On 4 May 2016 at 04:41, Suzuki K Poulose <suzuki.poulose@arm.com> wrote:
> Enabling a component via sysfs (echo 1 > enable_source), would
> trigger building a path from the enabled sources to the sink.
> If there is an error in the process (e.g, sink not enabled or
> the device (CPU corresponding to ETM) is not online), we never report
> failure, except for leaving a message in the dmesg.
>
> Do proper error checking for the build path and return the error.
>
> Before:
> $ echo 0 > /sys/devices/system/cpu/cpu2/online
> $ echo 1 > /sys/devices/cs_etm/cpu2/enable_source
> $ echo $?
> 0
>
> After:
> $ echo 0 > /sys/devices/system/cpu/cpu2/online
> $ echo 1 > /sys/devices/cs_etm/cpu2/enable_source
> -bash: echo: write error: No such device or address
>
> Cc: Mathie Porier <mathieu.poirier@linaro.org>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>

This patch looks good - thanks for the fix. Due to how late we are in
the cycle I'd ask Greg to pick it up right away but there is a
(couple) of typos in my name on the CC line. Either resend another
patch with the correct spelling or remove the CC line altogether.

Thanks,
Mathieu

> ---
> drivers/hwtracing/coresight/coresight.c | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
> index 2ea5961..e0c5166 100644
> --- a/drivers/hwtracing/coresight/coresight.c
> +++ b/drivers/hwtracing/coresight/coresight.c
> @@ -393,6 +393,7 @@ out:
> struct list_head *coresight_build_path(struct coresight_device *csdev)
> {
> struct list_head *path;
> + int rc;
>
> path = kzalloc(sizeof(struct list_head), GFP_KERNEL);
> if (!path)
> @@ -400,9 +401,10 @@ struct list_head *coresight_build_path(struct coresight_device *csdev)
>
> INIT_LIST_HEAD(path);
>
> - if (_coresight_build_path(csdev, path)) {
> + rc = _coresight_build_path(csdev, path);
> + if (rc) {
> kfree(path);
> - path = NULL;
> + return ERR_PTR(rc);
> }
>
> return path;
> @@ -448,8 +450,9 @@ int coresight_enable(struct coresight_device *csdev)
> goto out;
>
> path = coresight_build_path(csdev);
> - if (!path) {
> + if (IS_ERR(path)) {
> pr_err("building path(s) failed\n");
> + ret = PTR_ERR(path);
> goto out;
> }
>
> --
> 1.7.9.5
>