memory: samsung: exynos5422-dmc: Fix refcount leak in of_get_dram_timings

of_parse_phandle() returns a node pointer with refcount
incremented, we should use of_node_put() on it when not need anymore.
This function doesn't call of_node_put() in some error paths.
To unify the structure, Add put_node label and goto it on errors.

Fixes: 6e7674c3c6df ("memory: Add DMC driver for Exynos5422")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://lore.kernel.org/r/20220602041721.64348-1-linmq006@gmail.com
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

diff --git a/drivers/memory/samsung/exynos5422-dmc.c b/drivers/memory/samsung/exynos5422-dmc.c
index 4733e7898ffe5379686afdad2f8bde52bbb72add..c491cd549644fa3429949976462091471be30358 100644 (file)
--- a/drivers/memory/samsung/exynos5422-dmc.c
+++ b/drivers/memory/samsung/exynos5422-dmc.c
@@ -1187,33 +1187,39 @@ 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)
-               return -ENOMEM;
+       if (!dmc->timing_row) {
+               ret = -ENOMEM;
+               goto put_node;
+       }
 
        dmc->timing_data = devm_kmalloc_array(dmc->dev, TIMING_COUNT,
                                              sizeof(u32), GFP_KERNEL);
-       if (!dmc->timing_data)
-               return -ENOMEM;
+       if (!dmc->timing_data) {
+               ret = -ENOMEM;
+               goto put_node;
+       }
 
        dmc->timing_power = devm_kmalloc_array(dmc->dev, TIMING_COUNT,
                                               sizeof(u32), GFP_KERNEL);
-       if (!dmc->timing_power)
-               return -ENOMEM;
+       if (!dmc->timing_power) {
+               ret = -ENOMEM;
+               goto put_node;
+       }
 
        dmc->timings = of_lpddr3_get_ddr_timings(np_ddr, dmc->dev,
                                                 DDR_TYPE_LPDDR3,
                                                 &dmc->timings_arr_size);
        if (!dmc->timings) {
-               of_node_put(np_ddr);
                dev_warn(dmc->dev, "could not get timings from DT\n");
-               return -EINVAL;
+               ret = -EINVAL;
+               goto put_node;
        }
 
        dmc->min_tck = of_lpddr3_get_min_tck(np_ddr, dmc->dev);
        if (!dmc->min_tck) {
-               of_node_put(np_ddr);
                dev_warn(dmc->dev, "could not get tck from DT\n");
-               return -EINVAL;
+               ret = -EINVAL;
+               goto put_node;
        }
 
        /* Sorted array of OPPs with frequency ascending */
@@ -1227,13 +1233,14 @@ static int of_get_dram_timings(struct exynos5_dmc *dmc)
                                             clk_period_ps);
        }
 
-       of_node_put(np_ddr);
 
        /* Take the highest frequency's timings as 'bypass' */
        dmc->bypass_timing_row = dmc->timing_row[idx - 1];
        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;
 }