From: Gabriele Mazzotta <gabriele.mzt@gmail.com>
To: srinivas.pandruvada@linux.intel.com, rjw@rjwysocki.net
Cc: lenb@kernel.org, viresh.kumar@linaro.org,
linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
Gabriele Mazzotta <gabriele.mzt@gmail.com>
Subject: [PATCH] Revert "cpufreq: intel_pstate: Fix ->set_policy() interface for no_turbo"
Date: Sat, 4 Aug 2018 17:29:32 +0200 [thread overview]
Message-ID: <20180804152932.3861-1-gabriele.mzt@gmail.com> (raw)
This change does not take into account that some BIOSes change
MSR_IA32_MISC_ENABLE_TURBO_DISABLE depending on the power source.
If the turbo is disabled when the system boots, policy.max_freq
is set to pstate.max_pstate. However, if the BIOS later enables
the turbo, the CPU will never be able to run at pstate.turbo_pstate.
Since now intel_pstate_set_policy() does its calculations using
pstate.max_freq and pstate.turbo_freq, we can always calculate
cpuinfo.max_freq using pstate.turbo_pstate, thus allowing system
with varying MSR_IA32_MISC_ENABLE_TURBO_DISABLE to run at full
speed when the turbo is enabled.
This reverts commit 983e600e88835f0321d1a0ea06f52d48b7b5a544.
Signed-off-by: Gabriele Mazzotta <gabriele.mzt@gmail.com>
---
drivers/cpufreq/intel_pstate.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 3c3971256130..4043aae2d611 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -2068,9 +2068,8 @@ static int __intel_pstate_cpu_init(struct cpufreq_policy *policy)
/* cpuinfo and default policy values */
policy->cpuinfo.min_freq = cpu->pstate.min_pstate * cpu->pstate.scaling;
update_turbo_state();
- policy->cpuinfo.max_freq = global.turbo_disabled ?
- cpu->pstate.max_pstate : cpu->pstate.turbo_pstate;
- policy->cpuinfo.max_freq *= cpu->pstate.scaling;
+ policy->cpuinfo.max_freq =
+ cpu->pstate.turbo_pstate * cpu->pstate.scaling;
intel_pstate_init_acpi_perf_limits(policy);
--
2.18.0
next reply other threads:[~2018-08-04 15:30 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-04 15:29 Gabriele Mazzotta [this message]
2018-08-04 17:31 ` [PATCH] Revert "cpufreq: intel_pstate: Fix ->set_policy() interface for no_turbo" Gabriele Mazzotta
2018-08-06 8:30 ` Rafael J. Wysocki
2018-08-06 16:49 ` Srinivas Pandruvada
2018-08-06 21:50 ` Gabriele Mazzotta
2018-08-06 22:11 ` Srinivas Pandruvada
2018-08-07 20:12 ` Gabriele Mazzotta
2018-08-07 21:22 ` Srinivas Pandruvada
2018-08-07 22:05 ` Gabriele Mazzotta
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