ARM: shmobile: Fix device node reference leakage in shmobile_init_delay

The of_find_compatible_node() function returns a new reference to the
found node. Instead of just adding of_node_put() calls, simplify the
code by moving the CPU identification logic inside the loop over cpu
nodes, in order to lower complexity from O(n) to O(1) by replacing
of_find_compatible_node() calls with of_device_is_compatible().

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Magnus Damm <damm+renesas@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
(cherry picked from commit edc8fb1d6ebdfc4efa009073586d3567c3368475)
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

diff --git a/arch/arm/mach-shmobile/timer.c b/arch/arm/mach-shmobile/timer.c
index 68bc0b8..942efdc 100644 (file)
--- a/arch/arm/mach-shmobile/timer.c
+++ b/arch/arm/mach-shmobile/timer.c
@@ -59,29 +59,37 @@ void __init shmobile_setup_delay(unsigned int max_cpu_core_mhz,
 
 void __init shmobile_init_delay(void)
 {
-       struct device_node *np, *parent;
-       u32 max_freq, freq;
-
-       max_freq = 0;
-
-       parent = of_find_node_by_path("/cpus");
-       if (parent) {
-               for_each_child_of_node(parent, np) {
-                       if (!of_property_read_u32(np, "clock-frequency", &freq))
-                               max_freq = max(max_freq, freq);
-               }
-               of_node_put(parent);
-       }
+       struct device_node *np, *cpus;
+       bool is_a8_a9 = false;
+       bool is_a15 = false;
+       u32 max_freq = 0;
+
+       cpus = of_find_node_by_path("/cpus");
+       if (!cpus)
+               return;
+
+       for_each_child_of_node(cpus, np) {
+               u32 freq;
+
+               if (!of_property_read_u32(np, "clock-frequency", &freq))
+                       max_freq = max(max_freq, freq);
 
-       if (max_freq) {
-               if (of_find_compatible_node(NULL, NULL, "arm,cortex-a8"))
-                       shmobile_setup_delay_hz(max_freq, 1, 3);
-               else if (of_find_compatible_node(NULL, NULL, "arm,cortex-a9"))
-                       shmobile_setup_delay_hz(max_freq, 1, 3);
-               else if (of_find_compatible_node(NULL, NULL, "arm,cortex-a15"))
-                       if (!IS_ENABLED(CONFIG_ARM_ARCH_TIMER))
-                               shmobile_setup_delay_hz(max_freq, 2, 4);
+               if (of_device_is_compatible(np, "arm,cortex-a8") ||
+                   of_device_is_compatible(np, "arm,cortex-a9"))
+                       is_a8_a9 = true;
+               else if (of_device_is_compatible(np, "arm,cortex-a15"))
+                       is_a15 = true;
        }
+
+       of_node_put(cpus);
+
+       if (!max_freq)
+               return;
+
+       if (is_a8_a9)
+               shmobile_setup_delay_hz(max_freq, 1, 3);
+       else if (is_a15 && !IS_ENABLED(CONFIG_ARM_ARCH_TIMER))
+               shmobile_setup_delay_hz(max_freq, 2, 4);
 }
 
 static void __init shmobile_late_time_init(void)