From 17ffd35809c34b9564edb10727d02eb62958ba5c Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 5 Jan 2021 19:20:29 +0100 Subject: [PATCH] cpufreq: intel_pstate: Use HWP capabilities in intel_cpufreq_adjust_perf() If turbo P-states cannot be used, either due to the configuration of the processor, or because intel_pstate is not allowed to used them, the maximum available P-state with HWP enabled corresponds to the HWP_CAP.GUARANTEED value which is not static. It can be adjusted by an out-of-band agent or during an Intel Speed Select performance level change, so long as it remains less than or equal to HWP_CAP.MAX. However, if turbo P-states cannot be used, intel_cpufreq_adjust_perf() always uses pstate.max_pstate (set during the initialization of the driver only) as the maximum available P-state, so it may miss a change of the HWP_CAP.GUARANTEED value. Prevent that from happening by modifyig intel_cpufreq_adjust_perf() to always read the "guaranteed" and "maximum turbo" performance levels from the cached HWP_CAP value. Fixes: a365ab6b9dfb ("cpufreq: intel_pstate: Implement the ->adjust_perf() callback") Signed-off-by: Rafael J. Wysocki Acked-by: Srinivas Pandruvada --- drivers/cpufreq/intel_pstate.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 1a660466dd75..32bc11851b8d 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -2653,12 +2653,13 @@ static void intel_cpufreq_adjust_perf(unsigned int cpunum, unsigned long capacity) { struct cpudata *cpu = all_cpu_data[cpunum]; + u64 hwp_cap = READ_ONCE(cpu->hwp_cap_cached); int old_pstate = cpu->pstate.current_pstate; int cap_pstate, min_pstate, max_pstate, target_pstate; update_turbo_state(); - cap_pstate = global.turbo_disabled ? cpu->pstate.max_pstate : - cpu->pstate.turbo_pstate; + cap_pstate = global.turbo_disabled ? HWP_GUARANTEED_PERF(hwp_cap) : + HWP_HIGHEST_PERF(hwp_cap); /* Optimization: Avoid unnecessary divisions. */