linux/drivers/base
Rafael J. Wysocki 0cc2b4e5a0 PM / QoS: Fix device resume latency PM QoS
The special value of 0 for device resume latency PM QoS means
"no restriction", but there are two problems with that.

First, device resume latency PM QoS requests with 0 as the
value are always put in front of requests with positive
values in the priority lists used internally by the PM QoS
framework, causing 0 to be chosen as an effective constraint
value.  However, that 0 is then interpreted as "no restriction"
effectively overriding the other requests with specific
restrictions which is incorrect.

Second, the users of device resume latency PM QoS have no
way to specify that *any* resume latency at all should be
avoided, which is an artificial limitation in general.

To address these issues, modify device resume latency PM QoS to
use S32_MAX as the "no constraint" value and 0 as the "no
latency at all" one and rework its users (the cpuidle menu
governor, the genpd QoS governor and the runtime PM framework)
to follow these changes.

Also add a special "n/a" value to the corresponding user space I/F
to allow user space to indicate that it cannot accept any resume
latencies at all for the given device.

Fixes: 85dc0b8a40 (PM / QoS: Make it possible to expose PM QoS latency constraints)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=197323
Reported-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Alex Shi <alex.shi@linaro.org>
Cc: All applicable <stable@vger.kernel.org>
2017-10-24 15:20:45 +02:00
..
power PM / QoS: Fix device resume latency PM QoS 2017-10-24 15:20:45 +02:00
regmap regmap: regmap-w1: Fix build troubles 2017-07-17 15:53:00 +01:00
test driver core: test_async: fix up typo found by 0-day 2016-11-29 22:06:42 +01:00
arch_topology.c base: arch_topology: fix section mismatch build warnings 2017-09-18 17:05:07 +02:00
attribute_container.c attribute_container: Fix typo 2016-08-31 15:13:56 +02:00
base.h driver core: make device_{add|remove}_groups() public 2017-07-22 11:59:23 +02:00
bus.c driver core: bus: Fix a potential double free 2017-08-31 18:57:30 +02:00
cacheinfo.c Merge branch 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-22 09:25:45 -08:00
class.c driver core: remove class_attrs from struct class 2017-06-09 10:41:00 +02:00
component.c Merge 4.5-rc4 into driver-core-next 2016-02-14 14:29:55 -08:00
container.c
core.c Do not disable driver and bus shutdown hook when class shutdown hook is set. 2017-08-28 18:02:46 +02:00
cpu.c PM / QoS: Fix device resume latency PM QoS 2017-10-24 15:20:45 +02:00
dd.c initcall_debug: add deferred probe times 2017-08-03 17:48:49 -07:00
devcoredump.c driver core: devcoredump: convert to use class_groups 2016-11-29 21:12:12 +01:00
devres.c devres: add devm_alloc_percpu() 2016-11-15 22:34:25 -05:00
devtmpfs.c statx: Add a system call to make enhanced file info available 2017-03-02 20:51:15 -05:00
dma-coherent.c dma-coherent: fix rmem_dma_device_init regression 2017-09-17 08:20:02 -07:00
dma-contiguous.c cma: Store a name in the cma structure 2017-04-18 20:41:12 +02:00
dma-mapping.c dma-coherent: remove the DMA_MEMORY_MAP and DMA_MEMORY_IO flags 2017-09-01 11:59:17 +02:00
driver.c driver core: add missing blank line after declaration 2015-03-25 14:36:30 +01:00
firmware_class.c Revert "firmware: add sanity check on shutdown/suspend" 2017-09-10 21:19:06 -07:00
firmware.c
hypervisor.c
init.c drivers: of/base: move of_init to driver_init 2015-05-26 19:55:56 -07:00
isa.c isa: Call isa_bus_init before dependent ISA bus drivers register 2016-06-17 20:47:11 -07:00
Kconfig firmware: Restore support for built-in firmware 2017-09-16 10:58:48 -07:00
Makefile arm, arm64: factorize common cpu capacity default code 2017-06-03 19:10:09 +09:00
map.c drivers: base: map: Use kmalloc_array instead of kmalloc 2015-03-25 14:35:08 +01:00
memory.c mm, memory_hotplug: remove zone restrictions 2017-09-06 17:27:25 -07:00
module.c base: make module_create_drivers_dir race-free 2016-06-15 19:21:31 -07:00
node.c mm: only display online cpus of the numa node 2017-10-13 16:18:32 -07:00
pinctrl.c driver core: fix automatic pinctrl management 2017-06-13 11:07:32 +02:00
platform-msi.c irqchip/MSI: Use irq_domain_update_bus_token instead of an open coded access 2017-06-22 18:29:17 +02:00
platform.c driver core: platform: Don't read past the end of "driver_override" buffer 2017-09-18 17:16:47 +02:00
property.c ACPI: properties: Align return codes of __acpi_node_get_property_reference() 2017-10-11 21:15:44 +02:00
soc.c base: soc: Allow early registration of a single SoC device 2017-03-29 21:43:26 +02:00
syscore.c genirq: Simplify wakeup mechanism 2014-09-01 13:48:59 +02:00
topology.c base: topology: constify attribute_group structures. 2017-08-28 17:49:22 +02:00
transport_class.c