On Thu, 10 Oct 2024 20:06:18 +0200
Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> wrote:
> Obtain the device node reference and allocate memory with
> scoped/cleanup.h to reduce error handling and make the code a bit
> simpler.
>
> The code is not equivalent in one minor aspect: outgoing parameter
> "*ntrips" will not be zeroed on errors of memory allocation. This
> difference is not important, because code was already not zeroing it in
> case of earlier errors and the only caller does not rely on ntrips being
> 0 in case of errors.
>
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
Trivial unrelated comment inline + maybe return_ptr() is the way to go as
Chen-Yu mentioned.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> ---
>
> Cc: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> Cc: Chen-Yu Tsai <wenst@xxxxxxxxxxxx>
>
> Changes in v4:
> 1. Significant change: kzalloc() also with scoped-handling so the entire
> error handling could be removed.
> 2. Due to above, drop review-tags (Chen-Yu, Jonathan).
>
> Changes in v2:
> 1. Drop left-over of_node_put in regular exit path (Chen-Yu)
> ---
> drivers/thermal/thermal_of.c | 31 ++++++++-----------------------
> 1 file changed, 8 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/thermal/thermal_of.c b/drivers/thermal/thermal_of.c
> index f0ffc0e335ba9406f4fd858d6c561f9d23f4b842..37db435b54b124abf25b1d75d6cc4fb75f1c1e5c 100644
> --- a/drivers/thermal/thermal_of.c
> +++ b/drivers/thermal/thermal_of.c
> @@ -95,11 +95,9 @@ static int thermal_of_populate_trip(struct device_node *np,
>
> static struct thermal_trip *thermal_of_trips_init(struct device_node *np, int *ntrips)
> {
> - struct thermal_trip *tt;
> - struct device_node *trips;
> int ret, count;
>
> - trips = of_get_child_by_name(np, "trips");
> + struct device_node *trips __free(device_node) = of_get_child_by_name(np, "trips");
> if (!trips) {
> pr_err("Failed to find 'trips' node\n");
> return ERR_PTR(-EINVAL);
> @@ -108,36 +106,23 @@ static struct thermal_trip *thermal_of_trips_init(struct device_node *np, int *n
> count = of_get_child_count(trips);
> if (!count) {
> pr_err("No trip point defined\n");
> - ret = -EINVAL;
> - goto out_of_node_put;
> + return ERR_PTR(-EINVAL);
> }
>
> - tt = kzalloc(sizeof(*tt) * count, GFP_KERNEL);
> - if (!tt) {
> - ret = -ENOMEM;
> - goto out_of_node_put;
> - }
> -
> - *ntrips = count;
> + struct thermal_trip *tt __free(kfree) = kzalloc(sizeof(*tt) * count, GFP_KERNEL);
Trivial and unrelated, but maybe kcalloc(count, sizeof(tt), GFP_KERNEL);
> + if (!tt)
> + return ERR_PTR(-ENOMEM);
>
> count = 0;
> for_each_child_of_node_scoped(trips, trip) {
> ret = thermal_of_populate_trip(trip, &tt[count++]);
> if (ret)
> - goto out_kfree;
> + return ERR_PTR(ret);
> }
>
> - of_node_put(trips);
> + *ntrips = count;
>
> - return tt;
> -
> -out_kfree:
> - kfree(tt);
> - *ntrips = 0;
> -out_of_node_put:
> - of_node_put(trips);
> -
> - return ERR_PTR(ret);
> + return no_free_ptr(tt);
> }
>
> static struct device_node *of_thermal_zone_find(struct device_node *sensor, int id)
>
