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Diffstat (limited to 'Documentation/power/pm_qos_interface.rst')
| -rw-r--r-- | Documentation/power/pm_qos_interface.rst | 16 |
1 files changed, 5 insertions, 11 deletions
diff --git a/Documentation/power/pm_qos_interface.rst b/Documentation/power/pm_qos_interface.rst index 69b0fe3e2542..4c008e2202f0 100644 --- a/Documentation/power/pm_qos_interface.rst +++ b/Documentation/power/pm_qos_interface.rst @@ -52,17 +52,11 @@ int cpu_latency_qos_request_active(handle): Returns if the request is still active, i.e. it has not been removed from the CPU latency QoS list. -int cpu_latency_qos_add_notifier(notifier): - Adds a notification callback function to the CPU latency QoS. The callback is - called when the aggregated value for the CPU latency QoS is changed. - -int cpu_latency_qos_remove_notifier(notifier): - Removes the notification callback function from the CPU latency QoS. - From user space: -The infrastructure exposes one device node, /dev/cpu_dma_latency, for the CPU +The infrastructure exposes two separate device nodes, /dev/cpu_dma_latency for +the CPU latency QoS and /dev/cpu_wakeup_latency for the CPU system wakeup latency QoS. Only processes can register a PM QoS request. To provide for automatic @@ -70,15 +64,15 @@ cleanup of a process, the interface requires the process to register its parameter requests as follows. To register the default PM QoS target for the CPU latency QoS, the process must -open /dev/cpu_dma_latency. +open /dev/cpu_dma_latency. To register a CPU system wakeup QoS limit, the +process must open /dev/cpu_wakeup_latency. As long as the device node is held open that process has a registered request on the parameter. To change the requested target value, the process needs to write an s32 value to the open device node. Alternatively, it can write a hex string for the value -using the 10 char long format e.g. "0x12345678". This translates to a -cpu_latency_qos_update_request() call. +using the 10 char long format e.g. "0x12345678". To remove the user mode request for a target value simply close the device node. |