x86: intel_epb: Take CONFIG_PM into account (9ed09853) · Commits · 戴 / test

Commit ("PM / arch: x86: MSR_IA32_ENERGY_PERF_BIAS sysfs interface") caused kernels built with CONFIG_PM unset to crash on systems supporting the Performance and Energy Bias Hint (EPB), because it attempts to add files to sysfs directories that don't exist on those systems. Prevent that from happening by taking CONFIG_PM into account so that the code depending on it is not compiled at all when it is not set. Fixes: ("PM / arch: x86: MSR_IA32_ENERGY_PERF_BIAS sysfs interface") Reported-by:

Ido Schimmel <idosch@mellanox.com> Tested-by:

Ido Schimmel <idosch@mellanox.com> Signed-off-by:

Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by:

Ingo Molnar <mingo@kernel.org>

arch/x86/kernel/cpu/intel_epb.c

+21 −1

Original line number	Diff line number	Diff line
		@@ -97,6 +97,7 @@ static void intel_epb_restore(void)
		wrmsrl(MSR_IA32_ENERGY_PERF_BIAS, (epb & ~EPB_MASK) \| val);
		}

		#ifdef CONFIG_PM
		static struct syscore_ops intel_epb_syscore_ops = {
		.suspend = intel_epb_save,
		.resume = intel_epb_restore,
		@@ -193,6 +194,25 @@ static int intel_epb_offline(unsigned int cpu)
		return 0;
		}

		static inline void register_intel_ebp_syscore_ops(void)
		{
		register_syscore_ops(&intel_epb_syscore_ops);
		}
		#else /* !CONFIG_PM */
		static int intel_epb_online(unsigned int cpu)
		{
		intel_epb_restore();
		return 0;
		}

		static int intel_epb_offline(unsigned int cpu)
		{
		return intel_epb_save();
		}

		static inline void register_intel_ebp_syscore_ops(void) {}
		#endif

		static __init int intel_epb_init(void)
		{
		int ret;
		@@ -206,7 +226,7 @@ static __init int intel_epb_init(void)
		if (ret < 0)
		goto err_out_online;

		register_syscore_ops(&intel_epb_syscore_ops);
		register_intel_ebp_syscore_ops();
		return 0;

		err_out_online:

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