From 5ae4a4b45d4396aa7f7c008c4ae9eca981d43f8c Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Tue, 2 Feb 2021 10:25:11 +0530 Subject: cpufreq: Remove CPUFREQ_STICKY flag During cpufreq driver's registration, if the ->init() callback for all the CPUs fail then there is not much point in keeping the driver around as it will only account for more of unnecessary noise, for example cpufreq core will try to suspend/resume the driver which never got registered properly. The removal of such a driver is avoided if the driver carries the CPUFREQ_STICKY flag. This was added way back [1] in 2004 and perhaps no one should ever need it now. A lot of drivers do set this flag, probably because they just copied it from other drivers. This was added earlier for some platforms [2] because their cpufreq drivers were getting registered before the CPUs were registered with subsys framework. And hence they used to fail. The same isn't true anymore though. The current code flow in the kernel is: start_kernel() -> kernel_init() -> kernel_init_freeable() -> do_basic_setup() -> driver_init() -> cpu_dev_init() -> subsys_system_register() //For CPUs -> do_initcalls() -> cpufreq_register_driver() Clearly, the CPUs will always get registered with subsys framework before any cpufreq driver can get probed. Remove the flag and update the relevant drivers. Link: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/include/linux/cpufreq.h?id=7cc9f0d9a1ab04cedc60d64fd8dcf7df224a3b4d # [1] Link: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/arch/arm/mach-sa1100/cpu-sa1100.c?id=f59d3bbe35f6268d729f51be82af8325d62f20f5 # [2] Signed-off-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki --- include/linux/cpufreq.h | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) (limited to 'include/linux') diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 9c8b7437b6cd..c8e40e91fe9b 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -387,8 +387,13 @@ struct cpufreq_driver { /* flags */ -/* driver isn't removed even if all ->init() calls failed */ -#define CPUFREQ_STICKY BIT(0) +/* + * Set by drivers that need to update internale upper and lower boundaries along + * with the target frequency and so the core and governors should also invoke + * the diver if the target frequency does not change, but the policy min or max + * may have changed. + */ +#define CPUFREQ_NEED_UPDATE_LIMITS BIT(0) /* loops_per_jiffy or other kernel "constants" aren't affected by frequency transitions */ #define CPUFREQ_CONST_LOOPS BIT(1) @@ -432,14 +437,6 @@ struct cpufreq_driver { */ #define CPUFREQ_IS_COOLING_DEV BIT(7) -/* - * Set by drivers that need to update internale upper and lower boundaries along - * with the target frequency and so the core and governors should also invoke - * the diver if the target frequency does not change, but the policy min or max - * may have changed. - */ -#define CPUFREQ_NEED_UPDATE_LIMITS BIT(8) - int cpufreq_register_driver(struct cpufreq_driver *driver_data); int cpufreq_unregister_driver(struct cpufreq_driver *driver_data); -- cgit v1.2.3 From 2f0531869fd22182e769b10dd6cf151861ede791 Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Tue, 2 Feb 2021 11:11:55 +0530 Subject: cpufreq: Remove unused flag CPUFREQ_PM_NO_WARN This flag is set by one of the drivers but it isn't used in the code otherwise. Remove the unused flag and update the driver. Signed-off-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki --- include/linux/cpufreq.h | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) (limited to 'include/linux') diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index c8e40e91fe9b..353969c7acd3 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -398,8 +398,11 @@ struct cpufreq_driver { /* loops_per_jiffy or other kernel "constants" aren't affected by frequency transitions */ #define CPUFREQ_CONST_LOOPS BIT(1) -/* don't warn on suspend/resume speed mismatches */ -#define CPUFREQ_PM_NO_WARN BIT(2) +/* + * Set by drivers that want the core to automatically register the cpufreq + * driver as a thermal cooling device. + */ +#define CPUFREQ_IS_COOLING_DEV BIT(2) /* * This should be set by platforms having multiple clock-domains, i.e. @@ -431,12 +434,6 @@ struct cpufreq_driver { */ #define CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING BIT(6) -/* - * Set by drivers that want the core to automatically register the cpufreq - * driver as a thermal cooling device. - */ -#define CPUFREQ_IS_COOLING_DEV BIT(7) - int cpufreq_register_driver(struct cpufreq_driver *driver_data); int cpufreq_unregister_driver(struct cpufreq_driver *driver_data); -- cgit v1.2.3