]> git.ipfire.org Git - thirdparty/kernel/stable.git/commit
cpufreq: CPPC: Avoid using CPUFREQ_ETERNAL as transition delay
authorRafael J. Wysocki <rafael.j.wysocki@intel.com>
Fri, 26 Sep 2025 10:19:41 +0000 (12:19 +0200)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Wed, 1 Oct 2025 11:56:57 +0000 (13:56 +0200)
commitf965d111e68f4a993cc44d487d416e3d954eea11
tree6632f4b46c92afd41b6b231e2ab94edc2785435f
parentf97aef092e199c10a3da96ae79b571edd5362faa
cpufreq: CPPC: Avoid using CPUFREQ_ETERNAL as transition delay

If cppc_get_transition_latency() returns CPUFREQ_ETERNAL to indicate a
failure to retrieve the transition latency value from the platform
firmware, the CPPC cpufreq driver will use that value (converted to
microseconds) as the policy transition delay, but it is way too large
for any practical use.

Address this by making the driver use the cpufreq's default
transition latency value (in microseconds) as the transition delay
if CPUFREQ_ETERNAL is returned by cppc_get_transition_latency().

Fixes: d4f3388afd48 ("cpufreq / CPPC: Set platform specific transition_delay_us")
Cc: 5.19+ <stable@vger.kernel.org> # 5.19
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Reviewed-by: Jie Zhan <zhanjie9@hisilicon.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Qais Yousef <qyousef@layalina.io>
drivers/cpufreq/cppc_cpufreq.c