From b4a11fa3331e163e177e76098fe1d8b12b87cf6b Mon Sep 17 00:00:00 2001 From: Wyes Karny Date: Mon, 29 May 2023 14:25:51 +0000 Subject: cpufreq: Fail driver register if it has adjust_perf without fast_switch If fast_switch_possible flag is set by the scaling driver, the governor is free to select fast_switch function even if adjust_perf is set. Some scaling drivers which use adjust_perf don't set fast_switch thinking that the governor would never fall back to fast_switch. But the governor can fall back to fast_switch even in runtime if frequency invariance is disabled due to some reason. This could crash the kernel if the driver didn't set the fast_switch function pointer. Therefore, fail driver registration if it has adjust_perf without fast_switch. Suggested-by: Rafael J. Wysocki Suggested-by: Viresh Kumar Signed-off-by: Wyes Karny Signed-off-by: Rafael J. Wysocki --- include/linux/cpufreq.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 26e2eb399484..172ff51c1b2a 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -340,7 +340,10 @@ struct cpufreq_driver { /* * ->fast_switch() replacement for drivers that use an internal * representation of performance levels and can pass hints other than - * the target performance level to the hardware. + * the target performance level to the hardware. This can only be set + * if ->fast_switch is set too, because in those cases (under specific + * conditions) scale invariance can be disabled, which causes the + * schedutil governor to fall back to the latter. */ void (*adjust_perf)(unsigned int cpu, unsigned long min_perf, -- cgit v1.2.3 From c88ad30e3f861c7be4e3b4995554e2b0754059b7 Mon Sep 17 00:00:00 2001 From: Mario Limonciello Date: Tue, 20 Jun 2023 12:24:33 -0500 Subject: cpufreq: amd-pstate: Add a kernel config option to set default mode Users are having more success with amd-pstate since the introduction of EPP and Guided modes. To expose the driver to more users by default introduce a kernel configuration option for setting the default mode. Users can use an integer to map out which default mode they want to use in lieu of a kernel command line option. This will default to EPP, but only if: 1) The CPU supports an MSR. 2) The system profile is identified 3) The system profile is identified as a non-server by the FADT. Link: https://gitlab.freedesktop.org/hadess/power-profiles-daemon/-/merge_requests/121 Acked-by: Huang Rui Reviewed-by: Gautham R. Shenoy Co-developed-by: Perry Yuan Signed-off-by: Perry Yuan Signed-off-by: Mario Limonciello Signed-off-by: Rafael J. Wysocki --- include/linux/amd-pstate.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/amd-pstate.h b/include/linux/amd-pstate.h index c10ebf8c42e6..446394f84606 100644 --- a/include/linux/amd-pstate.h +++ b/include/linux/amd-pstate.h @@ -94,7 +94,8 @@ struct amd_cpudata { * enum amd_pstate_mode - driver working mode of amd pstate */ enum amd_pstate_mode { - AMD_PSTATE_DISABLE = 0, + AMD_PSTATE_UNDEFINED = 0, + AMD_PSTATE_DISABLE, AMD_PSTATE_PASSIVE, AMD_PSTATE_ACTIVE, AMD_PSTATE_GUIDED, @@ -102,6 +103,7 @@ enum amd_pstate_mode { }; static const char * const amd_pstate_mode_string[] = { + [AMD_PSTATE_UNDEFINED] = "undefined", [AMD_PSTATE_DISABLE] = "disable", [AMD_PSTATE_PASSIVE] = "passive", [AMD_PSTATE_ACTIVE] = "active", -- cgit v1.2.3