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authorPavel Machek <pavel@ucw.cz>2020-09-19 12:34:58 +0300
committerPavel Machek <pavel@ucw.cz>2020-09-30 20:15:40 +0300
commitabcc131292aa8c7de2c5f0ed76a717436c21de63 (patch)
tree80c17af851c1332247630cd7f323dfaef04dcc83 /drivers
parent364682d1bc16277b67f31e411a00e13c50002d2e (diff)
downloadlinux-abcc131292aa8c7de2c5f0ed76a717436c21de63.tar.xz
ledtrig-cpu: Limit to 8 CPUs
Some machines have thousands of CPUs... and trigger mechanisms was not really meant for thousands of triggers. I doubt anyone uses this trigger on many-CPU machine; but if they do, they'll need to do it properly. Signed-off-by: Pavel Machek <pavel@ucw.cz>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/leds/trigger/ledtrig-cpu.c13
1 files changed, 10 insertions, 3 deletions
diff --git a/drivers/leds/trigger/ledtrig-cpu.c b/drivers/leds/trigger/ledtrig-cpu.c
index 869976d1b734..fca62d503590 100644
--- a/drivers/leds/trigger/ledtrig-cpu.c
+++ b/drivers/leds/trigger/ledtrig-cpu.c
@@ -2,14 +2,18 @@
/*
* ledtrig-cpu.c - LED trigger based on CPU activity
*
- * This LED trigger will be registered for each possible CPU and named as
- * cpu0, cpu1, cpu2, cpu3, etc.
+ * This LED trigger will be registered for first 8 CPUs and named
+ * as cpu0..cpu7. There's additional trigger called cpu that
+ * is on when any CPU is active.
+ *
+ * If you want support for arbitrary number of CPUs, make it one trigger,
+ * with additional sysfs file selecting which CPU to watch.
*
* It can be bound to any LED just like other triggers using either a
* board file or via sysfs interface.
*
* An API named ledtrig_cpu is exported for any user, who want to add CPU
- * activity indication in their code
+ * activity indication in their code.
*
* Copyright 2011 Linus Walleij <linus.walleij@linaro.org>
* Copyright 2011 - 2012 Bryan Wu <bryan.wu@canonical.com>
@@ -145,6 +149,9 @@ static int __init ledtrig_cpu_init(void)
for_each_possible_cpu(cpu) {
struct led_trigger_cpu *trig = &per_cpu(cpu_trig, cpu);
+ if (cpu >= 8)
+ continue;
+
snprintf(trig->name, MAX_NAME_LEN, "cpu%d", cpu);
led_trigger_register_simple(trig->name, &trig->_trig);