Messages in this thread Patch in this message |  | | From | "Rafael J. Wysocki" <> | Subject | [PATCH] cpufreq: intel_pstate: Fix fast-switch fallback path | Date | Tue, 29 Dec 2020 18:15:23 +0100 |
| |
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When sugov_update_single_perf() falls back to the "frequency" path due to the missing scale-invariance, it will call cpufreq_driver_fast_switch() via sugov_fast_switch() and the driver's ->fast_switch() callback will be invoked, so it must not be NULL.
However, after commit a365ab6b9dfb ("cpufreq: intel_pstate: Implement the ->adjust_perf() callback") intel_pstate sets ->fast_switch() to NULL when it is going to use intel_cpufreq_adjust_perf(), which is a mistake, because on x86 the scale-invariance may be turned off dynamically, so modify it to retain the original ->adjust_perf() callback pointer.
Fixes: a365ab6b9dfb ("cpufreq: intel_pstate: Implement the ->adjust_perf() callback") Reported-by: Kenneth R. Crudup <kenny@panix.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> --- drivers/cpufreq/intel_pstate.c | 1 - 1 file changed, 1 deletion(-)
Index: linux-pm/drivers/cpufreq/intel_pstate.c =================================================================== --- linux-pm.orig/drivers/cpufreq/intel_pstate.c +++ linux-pm/drivers/cpufreq/intel_pstate.c @@ -3088,7 +3088,6 @@ static int __init intel_pstate_init(void intel_pstate.attr = hwp_cpufreq_attrs; intel_cpufreq.attr = hwp_cpufreq_attrs; intel_cpufreq.flags |= CPUFREQ_NEED_UPDATE_LIMITS; - intel_cpufreq.fast_switch = NULL; intel_cpufreq.adjust_perf = intel_cpufreq_adjust_perf; if (!default_driver) default_driver = &intel_pstate;
|  |