user/sven/linux.git/drivers/cpuidle/driver.c, branch v5.9.2

cpuidle: Drop unused cpuidle_driver_ref/unref() functions

2020-01-09T15:47:22Z

The cpuidle_driver_ref() and cpuidle_driver_unref() functions are not used and the refcnt field in struct cpuidle_driver operated by them is not updated anywhere else (so it is permanently equal to 0), so drop both of them along with refcnt. Signed-off-by: Rafael J. Wysocki Acked-by: Daniel Lezcano

cpuidle: Fix cpuidle_driver_state_disabled()

2019-12-10T22:41:20Z

It turns out that cpuidle_driver_state_disabled() can be called before registering the cpufreq driver on some platforms, which was not expected when it was introduced and which leads to a NULL pointer dereference when trying to walk the CPUs associated with the given cpuidle driver. Fix the problem by making cpuidle_driver_state_disabled() check if the driver's mask of CPUs associated with it is present and to set CPUIDLE_FLAG_UNUSABLE for the given idle state in the driver's states list if that is not the case to cause __cpuidle_register_device() to set CPUIDLE_STATE_DISABLED_BY_DRIVER for that state for all cpuidle devices registered by it later. Fixes: cbda56d5fefc ("cpuidle: Introduce cpuidle_driver_state_disabled() for driver quirks") Reported-by: Daniel Lezcano Tested-by: Daniel Lezcano Signed-off-by: Rafael J. Wysocki

cpuidle: Introduce cpuidle_driver_state_disabled() for driver quirks

2019-11-19T09:35:13Z

Commit 99e98d3fb100 ("cpuidle: Consolidate disabled state checks") overlooked the fact that the imx6q and tegra20 cpuidle drivers use the "disabled" field in struct cpuidle_state for quirks which trigger after the initialization of cpuidle, so reading the initial value of that field is not sufficient for those drivers. In order to allow them to implement the quirks without using the "disabled" field in struct cpuidle_state, introduce a new helper function and modify them to use it. Fixes: 99e98d3fb100 ("cpuidle: Consolidate disabled state checks") Reported-by: Len Brown Signed-off-by: Rafael J. Wysocki

cpuidle: Use nanoseconds as the unit of time

2019-11-11T20:56:07Z

Currently, the cpuidle subsystem uses microseconds as the unit of time which (among other things) causes the idle loop to incur some integer division overhead for no clear benefit. In order to allow cpuidle to measure time in nanoseconds, add two new fields, exit_latency_ns and target_residency_ns, to represent the exit latency and target residency of an idle state in nanoseconds, respectively, to struct cpuidle_state and initialize them with the help of the corresponding values in microseconds provided by drivers. Additionally, change cpuidle_governor_latency_req() to return the idle state exit latency constraint in nanoseconds. Also meeasure idle state residency (last_residency_ns in struct cpuidle_device and time_ns in struct cpuidle_driver) in nanoseconds and update the cpuidle core and governors accordingly. However, the menu governor still computes typical intervals in microseconds to avoid integer overflows. Signed-off-by: Rafael J. Wysocki Acked-by: Peter Zijlstra (Intel) Acked-by: Doug Smythies Tested-by: Doug Smythies

cpuidle: Do not unset the driver if it is there already

2019-10-24T21:22:33Z

Fix __cpuidle_set_driver() to check if any of the CPUs in the mask has a driver different from drv already and, if so, return -EBUSY before updating any cpuidle_drivers per-CPU pointers. Fixes: 82467a5a885d ("cpuidle: simplify multiple driver support") Cc: 3.11+ # 3.11+ Signed-off-by: Zhenzhong Duan [ rjw: Subject & changelog ] Signed-off-by: Rafael J. Wysocki

cpuidle: allow governor switch on cpuidle_register_driver()

2019-09-11T15:36:30Z

The recently introduced haltpoll driver is largely only useful with haltpoll governor. To allow drivers to associate with a particular idle behaviour, add a @governor property to 'struct cpuidle_driver' and thus allow a cpuidle driver to switch to a *preferred* governor on idle driver registration. We save the previous governor, and when an idle driver is unregistered we switch back to that. The @governor can be overridden by cpuidle.governor= boot param or alternatively be ignored if the governor doesn't exist. Signed-off-by: Joao Martins Signed-off-by: Rafael J. Wysocki

cpuidle: Make drivers initialize polling state

2017-08-30T01:06:33Z

Make the drivers that want to include the polling state into their states table initialize it explicitly and drop the initialization of it (which in fact is conditional, but that is not obvious from the code) from the core. Signed-off-by: Rafael J. Wysocki Tested-by: Sudeep Holla Acked-by: Daniel Lezcano

cpuidle: Move polling state initialization code to separate file

2017-08-30T01:06:27Z

Move the polling state initialization code to a separate file built conditionally on CONFIG_ARCH_HAS_CPU_RELAX to get rid of the #ifdef in driver.c. Signed-off-by: Rafael J. Wysocki Tested-by: Sudeep Holla Acked-by: Daniel Lezcano

cpuidle: Eliminate the CPUIDLE_DRIVER_STATE_START symbol

2017-08-30T01:05:29Z

On some architectures the first (index 0) idle state is a polling one and it doesn't really save energy, so there is the CPUIDLE_DRIVER_STATE_START symbol allowing some pieces of cpuidle code to avoid using that state. However, this makes the code rather hard to follow. It is better to explicitly avoid the polling state, so add a new cpuidle state flag CPUIDLE_FLAG_POLLING to mark it and make the relevant code check that flag for the first state instead of using the CPUIDLE_DRIVER_STATE_START symbol. In the ACPI processor driver that cannot always rely on the state flags (like before the states table has been set up) define a new internal symbol ACPI_IDLE_STATE_START equivalent to the CPUIDLE_DRIVER_STATE_START one and drop the latter. Signed-off-by: Rafael J. Wysocki Tested-by: Sudeep Holla Acked-by: Daniel Lezcano

sched/headers: Prepare for new header dependencies before moving code to

2017-03-02T07:42:26Z

We are going to split out of , which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder file that just maps to to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar