drm/amdgpu/pm: document power_dpm_state

This is a legacy file and is only provided for
backwards compatibility.

Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Alex Deucher 2018-04-19 13:56:41 -05:00
parent 8567f68147
commit ca8d40ca19

View File

@ -77,6 +77,37 @@ void amdgpu_pm_acpi_event_handler(struct amdgpu_device *adev)
}
}
/**
* DOC: power_dpm_state
*
* This is a legacy interface and is only provided for backwards compatibility.
* The amdgpu driver provides a sysfs API for adjusting certain power
* related parameters. The file power_dpm_state is used for this.
* It accepts the following arguments:
* - battery
* - balanced
* - performance
*
* battery
*
* On older GPUs, the vbios provided a special power state for battery
* operation. Selecting battery switched to this state. This is no
* longer provided on newer GPUs so the option does nothing in that case.
*
* balanced
*
* On older GPUs, the vbios provided a special power state for balanced
* operation. Selecting balanced switched to this state. This is no
* longer provided on newer GPUs so the option does nothing in that case.
*
* performance
*
* On older GPUs, the vbios provided a special power state for performance
* operation. Selecting performance switched to this state. This is no
* longer provided on newer GPUs so the option does nothing in that case.
*
*/
static ssize_t amdgpu_get_dpm_state(struct device *dev,
struct device_attribute *attr,
char *buf)