diff options
| author | Zhenzhong Duan <zhenzhong.duan@oracle.com> | 2019-10-23 09:57:14 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-12-21 10:42:04 +0100 |
| commit | 5751ba7db7d354dfdb491b9a83b24ea3d176d816 (patch) | |
| tree | 1acec01d77cc6528b992d89114daa6af7c87bacf /drivers/cpuidle | |
| parent | 8d95d0812b1decaf5846792ce4eb750c274cc38a (diff) | |
cpuidle: Do not unset the driver if it is there already
commit 918c1fe9fbbe46fcf56837ff21f0ef96424e8b29 upstream.
Fix __cpuidle_set_driver() to check if any of the CPUs in the mask has
a driver different from drv already and, if so, return -EBUSY before
updating any cpuidle_drivers per-CPU pointers.
Fixes: 82467a5a885d ("cpuidle: simplify multiple driver support")
Cc: 3.11+ <stable@vger.kernel.org> # 3.11+
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/cpuidle')
| -rw-r--r-- | drivers/cpuidle/driver.c | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c index ab264d393233..3780e1aa6807 100644 --- a/drivers/cpuidle/driver.c +++ b/drivers/cpuidle/driver.c @@ -61,24 +61,23 @@ static inline void __cpuidle_unset_driver(struct cpuidle_driver *drv) * __cpuidle_set_driver - set per CPU driver variables for the given driver. * @drv: a valid pointer to a struct cpuidle_driver * - * For each CPU in the driver's cpumask, unset the registered driver per CPU - * to @drv. - * - * Returns 0 on success, -EBUSY if the CPUs have driver(s) already. + * Returns 0 on success, -EBUSY if any CPU in the cpumask have a driver + * different from drv already. */ static inline int __cpuidle_set_driver(struct cpuidle_driver *drv) { int cpu; for_each_cpu(cpu, drv->cpumask) { + struct cpuidle_driver *old_drv; - if (__cpuidle_get_cpu_driver(cpu)) { - __cpuidle_unset_driver(drv); + old_drv = __cpuidle_get_cpu_driver(cpu); + if (old_drv && old_drv != drv) return -EBUSY; - } + } + for_each_cpu(cpu, drv->cpumask) per_cpu(cpuidle_drivers, cpu) = drv; - } return 0; } |