[PATCH 6.6 014/143] cpufreq: intel_pstate: fix pstate limits enforcement for adjust_perf call back

Greg Kroah-Hartman
2024-03-04T21:36:33Z

From: Doug Smythies <dsmythies@telus.net>

[ Upstream commit f0a0fc10abb062d122db5ac4ed42f6d1ca342649 ]

There is a loophole in pstate limit clamping for the intel_cpufreq CPU
frequency scaling driver (intel_pstate in passive mode), schedutil CPU
frequency scaling governor, HWP (HardWare Pstate) control enabled, when
the adjust_perf call back path is used.

Fix it.

Fixes: a365ab6b9dfb cpufreq: intel_pstate: Implement the ->adjust_perf() callback
Signed-off-by: Doug Smythies <dsmythies@telus.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/cpufreq/intel_pstate.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index c352a593e5d86..586a58d761bb6 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -2987,6 +2987,9 @@ static void intel_cpufreq_adjust_perf(unsigned int cpunum,
if (min_pstate < cpu->min_perf_ratio)
min_pstate = cpu->min_perf_ratio;

+ if (min_pstate > cpu->max_perf_ratio)
+ min_pstate = cpu->max_perf_ratio;
+
max_pstate = min(cap_pstate, cpu->max_perf_ratio);
if (max_pstate < min_pstate)
max_pstate = min_pstate;
--
2.43.0