Re: [PATCH 3/9] memory: samsung: exynos5422-dmc: use scoped device node handling to simplify error paths

Jonathan Cameron
2024-08-14T16:42:51Z

On Mon, 12 Aug 2024 15:33:57 +0200
Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> wrote:

> Obtain the device node reference with scoped/cleanup.h to reduce error
> handling and make the code a bit simpler.
>
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Trivial comments inline
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> ---
> drivers/memory/samsung/exynos5422-dmc.c | 31 +++++++++++--------------------
> 1 file changed, 11 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/memory/samsung/exynos5422-dmc.c b/drivers/memory/samsung/exynos5422-dmc.c
> index da7ecd921c72..d3ae4d95a3ba 100644
> --- a/drivers/memory/samsung/exynos5422-dmc.c
> +++ b/drivers/memory/samsung/exynos5422-dmc.c
> @@ -4,6 +4,7 @@
> * Author: Lukasz Luba <l.luba@partner.samsung.com>
> */
>
> +#include <linux/cleanup.h>
> #include <linux/clk.h>
> #include <linux/devfreq.h>
> #include <linux/devfreq-event.h>
> @@ -1176,10 +1177,10 @@ static int of_get_dram_timings(struct exynos5_dmc *dmc)
> {
> int ret = 0;
> int idx;
> - struct device_node *np_ddr;

This would definitely benefit from a
struct device *dev = dmc->dev;

> u32 freq_mhz, clk_period_ps;
>
> - np_ddr = of_parse_phandle(dmc->dev->of_node, "device-handle", 0);
> + struct device_node *np_ddr __free(device_node) = of_parse_phandle(dmc->dev->of_node,
> + "device-handle", 0);
Trivial. Maybe consider the wrap suggested in patch 1.
> + struct device_node *np_ddr __free(device_node) =
of_parse_phandle(dmc->dev->of_node, "device-handle", 0);

> if (!np_ddr) {
> dev_warn(dmc->dev, "could not find 'device-handle' in DT\n");
> return -EINVAL;
> @@ -1187,39 +1188,31 @@ static int of_get_dram_timings(struct exynos5_dmc *dmc)
>
> dmc->timing_row = devm_kmalloc_array(dmc->dev, TIMING_COUNT,
> sizeof(u32), GFP_KERNEL);
> - if (!dmc->timing_row) {
> - ret = -ENOMEM;
> - goto put_node;
> - }
> + if (!dmc->timing_row)
> + return -ENOMEM;
>
> dmc->timing_data = devm_kmalloc_array(dmc->dev, TIMING_COUNT,
> sizeof(u32), GFP_KERNEL);
> - if (!dmc->timing_data) {
> - ret = -ENOMEM;
> - goto put_node;
> - }
> + if (!dmc->timing_data)
> + return -ENOMEM;
>
> dmc->timing_power = devm_kmalloc_array(dmc->dev, TIMING_COUNT,
> sizeof(u32), GFP_KERNEL);
> - if (!dmc->timing_power) {
> - ret = -ENOMEM;
> - goto put_node;
> - }
> + if (!dmc->timing_power)
> + return -ENOMEM;
>
> dmc->timings = of_lpddr3_get_ddr_timings(np_ddr, dmc->dev,
> DDR_TYPE_LPDDR3,
> &dmc->timings_arr_size);
> if (!dmc->timings) {
> dev_warn(dmc->dev, "could not get timings from DT\n");
> - ret = -EINVAL;
> - goto put_node;
> + return -EINVAL;
> }
>
> dmc->min_tck = of_lpddr3_get_min_tck(np_ddr, dmc->dev);
> if (!dmc->min_tck) {
> dev_warn(dmc->dev, "could not get tck from DT\n");
> - ret = -EINVAL;
> - goto put_node;
> + return -EINVAL;
> }
>
> /* Sorted array of OPPs with frequency ascending */
> @@ -1239,8 +1232,6 @@ static int of_get_dram_timings(struct exynos5_dmc *dmc)
> dmc->bypass_timing_data = dmc->timing_data[idx - 1];
> dmc->bypass_timing_power = dmc->timing_power[idx - 1];
>
> -put_node:
> - of_node_put(np_ddr);
> return ret;
> }
>
>