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| author |   Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2017-10-24 15:20:45 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2017-10-24 15:20:45 +0200 |
| commit | 0cc2b4e5a020fc7f4d1795741c116c983e9467d7 (patch) | |
| tree | 38602fa4c8dccc952cac0b100bdd4673cf15bf79 /include | |
| parent | Linux 4.14-rc6 (diff) | |
| download | linux-dev-0cc2b4e5a020fc7f4d1795741c116c983e9467d7.tar.xz linux-dev-0cc2b4e5a020fc7f4d1795741c116c983e9467d7.zip | |
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: 85dc0b8a4019 (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>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/pm_qos.h | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h index 032b55909145..6737a8c9e8c6 100644 --- a/include/linux/pm_qos.h +++ b/include/linux/pm_qos.h @@ -27,16 +27,17 @@ enum pm_qos_flags_status { PM_QOS_FLAGS_ALL, }; -#define PM_QOS_DEFAULT_VALUE -1 +#define PM_QOS_DEFAULT_VALUE (-1) +#define PM_QOS_LATENCY_ANY S32_MAX #define PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE (2000 * USEC_PER_SEC) #define PM_QOS_NETWORK_LAT_DEFAULT_VALUE (2000 * USEC_PER_SEC) #define PM_QOS_NETWORK_THROUGHPUT_DEFAULT_VALUE 0 #define PM_QOS_MEMORY_BANDWIDTH_DEFAULT_VALUE 0 #define PM_QOS_RESUME_LATENCY_DEFAULT_VALUE 0 +#define PM_QOS_RESUME_LATENCY_NO_CONSTRAINT PM_QOS_LATENCY_ANY #define PM_QOS_LATENCY_TOLERANCE_DEFAULT_VALUE 0 #define PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT (-1) -#define PM_QOS_LATENCY_ANY ((s32)(~(__u32)0 >> 1)) #define PM_QOS_FLAG_NO_POWER_OFF (1 << 0) #define PM_QOS_FLAG_REMOTE_WAKEUP (1 << 1) |