cpu/hotplug: Allowing to reset fail injection

Currently, the only way of resetting the fail injection is to trigger a
hotplug, hotunplug or both. This is rather annoying for testing
and, as the default value for this file is -1, it seems pretty natural to
let a user write it.

Signed-off-by: Vincent Donnefort <vincent.donnefort@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20210216103506.416286-2-vincent.donnefort@arm.com

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 1b6302e..9121edf 100644 (file)
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -2207,6 +2207,11 @@ static ssize_t write_cpuhp_fail(struct device *dev,
        if (ret)
                return ret;
 
+       if (fail == CPUHP_INVALID) {
+               st->fail = fail;
+               return count;
+       }
+
        if (fail < CPUHP_OFFLINE || fail > CPUHP_ONLINE)
                return -EINVAL;