cpuidle: Do not unset the driver if it is there already (918c1fe9) · Commits · 戴 / test

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: ("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>

drivers/cpuidle/driver.c

+7 −8

Original line number	Diff line number	Diff line
		@@ -62,24 +62,23 @@ 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;
		}

Admin message