kernel/git/stable/linux.git/drivers/cpufreq, branch linux-6.18.y

cpufreq/amd-pstate: Allow writes to dynamic_epp when state isn't modified

2026-09-14T11:36:19+00:00

[ Upstream commit c5eed6ddc757e477f52b3d99bfde9e59975c72ca ] Writing the current "dynamic_epp" state to sysfs fails with -EINVAL even though the desired result was achieved. Allow writes to "dynamic_epp" that does not modify the state. Fixes: e30ca6dd5345 ("cpufreq/amd-pstate: Add dynamic energy performance preference") Reviewed-by: Mario Limonciello Signed-off-by: K Prateek Nayak Link: https://lore.kernel.org/r/20260508051748.10484-4-kprateek.nayak@amd.com Signed-off-by: Mario Limonciello (AMD) Signed-off-by: Sasha Levin

cpufreq/amd-pstate: Use "epp_default_dc" as default when dynamic_epp is disabled

2026-09-14T11:36:19+00:00

[ Upstream commit caa822d312be54e3fe1a3b52c887e0888e149c12 ] If "dynamic_epp" is disabled, the driver initialization and the default EPP selection from sysfs currently sets the EPP based on the power supply state of the system at that time but there is no power supply callbacks registered to toggle it when the power supply state changes. This can lead to faster battery drain on platforms that start off while being plugged to the wall but later move to battery power since the EPP stays at AMD_CPPC_EPP_PERFORMANCE. Use "epp_default_dc" as the default EPP selection when dynamic_epp is disabled, restoring older behavior. On servers, this defaults to AMD_CPPC_EPP_PERFORMANCE and on other platforms, it defaults to AMD_CPPC_EPP_BALANCE_PERFORMANCE. Fixes: e30ca6dd5345 ("cpufreq/amd-pstate: Add dynamic energy performance preference") Reviewed-by: Mario Limonciello Signed-off-by: K Prateek Nayak Link: https://lore.kernel.org/r/20260508051748.10484-6-kprateek.nayak@amd.com Signed-off-by: Mario Limonciello (AMD) Signed-off-by: Sasha Levin

cpufreq/amd-pstate: Add support for raw EPP writes

2026-09-14T11:36:19+00:00

[ Upstream commit 6927f21852f38db2975b5d5539cbe5241c25a99b ] The energy performance preference field of the CPPC request MSR supports values from 0 to 255, but the strings only offer 4 values. The other values are useful for tuning the performance of some workloads. Add support for writing the raw energy performance preference value to the sysfs file. If the last value written was an integer then an integer will be returned. If the last value written was a string then a string will be returned. Reviewed-by: Gautham R. Shenoy Signed-off-by: Mario Limonciello (AMD) Stable-dep-of: caa822d312be ("cpufreq/amd-pstate: Use "epp_default_dc" as default when dynamic_epp is disabled") Signed-off-by: Sasha Levin

cpufreq/amd-pstate: Add static asserts for EPP indices

2026-09-14T11:36:18+00:00

[ Upstream commit 077f23573d29d063a950e90aa77c8e1f79580147 ] In case a new index is introduced add a static assert to make sure that strings and values are updated. Reviewed-by: Gautham R. Shenoy Signed-off-by: Mario Limonciello (AMD) Stable-dep-of: caa822d312be ("cpufreq/amd-pstate: Use "epp_default_dc" as default when dynamic_epp is disabled") Signed-off-by: Sasha Levin

cpufreq/amd-pstate: Fix some whitespace issues

2026-09-14T11:36:18+00:00

[ Upstream commit e9d62ca86a5525a742742fe69e9aa316cfd4f471 ] Add whitespace around the equals and remove leading space. Reviewed-by: Gautham R. Shenoy Signed-off-by: Mario Limonciello (AMD) Stable-dep-of: caa822d312be ("cpufreq/amd-pstate: Use "epp_default_dc" as default when dynamic_epp is disabled") Signed-off-by: Sasha Levin

cpufreq/amd-pstate: Fix setting EPP in performance mode

2026-09-14T11:36:16+00:00

[ Upstream commit 5629eec1a2829871d496f3042884cdc267612f6a ] EPP 0 is the only supported value in the performance policy. commit 798c47593cca ("cpufreq/amd-pstate: Add support for platform profile class") changed this while adding platform profile support to the dynamic EPP feature, but this actually wasn't necessary since platform profile writes disable manual EPP writes. Restore allowing writing EPP of 0 when in performance mode. Reviewed-by: Marco Scardovi Tested-by: Marco Scardovi Reported-by: Stuart Meckle Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221473 Closes: https://gitlab.freedesktop.org/upower/power-profiles-daemon/-/work_items/190 Fixes: 798c47593cca ("cpufreq/amd-pstate: Add support for platform profile class") Signed-off-by: Mario Limonciello (AMD) Signed-off-by: Sasha Levin

cpufreq/amd-pstate: Add POWER_SUPPLY select for dynamic EPP

2026-09-14T11:36:16+00:00

[ Upstream commit 679343977588781bd3effba79e9644aee4ee046c ] The dynamic EPP feature uses power_supply_reg_notifier() and power_supply_unreg_notifier() but doesn't declare a dependency on POWER_SUPPLY, causing linker errors when POWER_SUPPLY is not enabled. Add POWER_SUPPLY to the selects. Suggested-by: K Prateek Nayak Fixes: e30ca6dd5345 ("cpufreq/amd-pstate: Add dynamic energy performance preference") Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202604040742.ySEdkuAa-lkp@intel.com/ Signed-off-by: Mario Limonciello Link: https://patch.msgid.link/20260407194949.310114-1-mario.limonciello@amd.com Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

cpufreq/amd-pstate: Grab "amd_pstate_driver_lock" when toggling dynamic_epp

2026-09-14T11:36:16+00:00

[ Upstream commit 9228169d2ae055ed09a163887fc59a710a5eb73b ] Concurrently changing driver mode and dynamic_epp with: echo passive > /sys/devices/system/cpu/amd_pstate/status& echo disable > /sys/devices/system/cpu/amd_pstate/dynamic_epp& hits the WARN_ON_ONCE() in static_key_disable_cpuslocked() and hangs the system since both sysfs writes are trying to do amd_pstate_change_driver_mode() without any synchronization. Grab the "amd_pstate_driver_lock" mutex when modifying "dynamic_epp" to prevent the two paths from racing with each other. Add a lockdep assertion for "amd_pstate_driver_lock" in amd_pstate_change_driver_mode() to formalize the dependency. Since "cppc_mode" is stable under "amd_pstate_driver_lock", only reload the driver when in "AMD_PSTATE_ACTIVE" mode and reject all writes when in passive or guided mode, or if the driver is not loaded, since only active mode operates on EPP. Fixes: e30ca6dd5345 ("cpufreq/amd-pstate: Add dynamic energy performance preference") Reviewed-by: Mario Limonciello Signed-off-by: K Prateek Nayak Link: https://lore.kernel.org/r/20260508051748.10484-2-kprateek.nayak@amd.com Signed-off-by: Mario Limonciello (AMD) Signed-off-by: Sasha Levin

cpufreq/amd-pstate: Return -ENOMEM on failure to allocate profile_name

2026-09-14T11:36:16+00:00

[ Upstream commit 87d2a8dec0f02b200eb3527da0ab11ba4d4e7deb ] Failure to allocate profile name will return -EINVAL from platform_profile_register() while in fact, it is a failure to allocate memory for the profile_name string. Return -ENOMEM when kasprintf() fails to allocate profile_name string. Fixes: e30ca6dd5345 ("cpufreq/amd-pstate: Add dynamic energy performance preference") Reviewed-by: Mario Limonciello Signed-off-by: K Prateek Nayak Link: https://lore.kernel.org/r/20260508051748.10484-3-kprateek.nayak@amd.com Signed-off-by: Mario Limonciello (AMD) Signed-off-by: Sasha Levin

cpufreq/amd-pstate: Reorder notifier unregistration and floor perf reset

2026-09-14T11:36:16+00:00

[ Upstream commit f3acf7ff113007557538b278ccb0e4ab7ae513ea ] An active power supply notifier can race with amd_pstate_epp_cpu_exit() trying to reset the floor perf and can overwrite the floor perf set in MSR_AMD_CPPC_REQ. Unregister the notifier before setting the floor perf to prevent the rare race. Fixes: e30ca6dd5345 ("cpufreq/amd-pstate: Add dynamic energy performance preference") Reviewed-by: Mario Limonciello Signed-off-by: K Prateek Nayak Link: https://lore.kernel.org/r/20260508051748.10484-5-kprateek.nayak@amd.com Signed-off-by: Mario Limonciello (AMD) Signed-off-by: Sasha Levin