linux_dsm_epyc7002/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
arch_topology.c base: arch_topology: fix section mismatch build warnings 2017-09-18 17:05:07 +02:00
attribute_container.c
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
class.c
component.c
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
devres.c
devtmpfs.c
dma-coherent.c dma-coherent: fix rmem_dma_device_init regression 2017-09-17 08:20:02 -07:00
dma-contiguous.c
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
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
isa.c
Kconfig firmware: Restore support for built-in firmware 2017-09-16 10:58:48 -07:00
Makefile
map.c
memory.c mm, memory_hotplug: remove zone restrictions 2017-09-06 17:27:25 -07:00
module.c
node.c mm: only display online cpus of the numa node 2017-10-13 16:18:32 -07:00
pinctrl.c
platform-msi.c
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
syscore.c
topology.c base: topology: constify attribute_group structures. 2017-08-28 17:49:22 +02:00
transport_class.c