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author | Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> | 2022-02-11 15:27:42 -0800 |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2022-02-25 20:49:29 +0100 |
commit | bea2d9868ef553e376480de3cd84a7a06fb03e41 (patch) | |
tree | fe882734bda538c25dc009161309f72173ce19c0 /drivers/acpi/fan_core.c | |
parent | d445571fa369cf08148dcd9bce563d5fae14fcd7 (diff) | |
download | linux-stable-bea2d9868ef553e376480de3cd84a7a06fb03e41.tar.gz linux-stable-bea2d9868ef553e376480de3cd84a7a06fb03e41.tar.bz2 linux-stable-bea2d9868ef553e376480de3cd84a7a06fb03e41.zip |
ACPI: fan: Properly handle fine grain control
When _FIF object specifies support for fine grain control, then fan speed
can be set from 0 to 100% with the recommended minimum "step size" via
_FSL object. Here the control value doesn't need to match any value from
_FPS object.
Currently we have a simple solution implemented which just pick maximum
control value from _FPS to display the actual state, but this is not
optimal when there is a big window between two control values in
_FPS. Also there is no way to set to any speed which doesn't match
control values in _FPS. The system firmware can start the fan at speed
which doesn't match any control value.
To support fine grain control (when supported) via thermal sysfs:
- cooling device max state is not _FPS state count but it will be
100 / _FIF.step_size
Step size can be from 1 to 9.
- cooling device current state is _FST.control / _FIF.step_size
- cooling device set state will set the control value
cdev.curr_state * _FIF.step_size plus any adjustment for 100%.
By the spec, when control value do not sum to 100% because of
_FIF.step_size, OSPM may select an appropriate ending Level increment
to reach 100%.
There is no rounding during calculation. For example if step size
is 6:
thermal sysfs cooling device max_state = 100/6 = 16
So user can set any value from 0-16.
If the system boots with a _FST.control which is not multiples
of step_size, the thermal sysfs cur_state will be based on the
range. For example for step size = 6:
_FST.control thermal sysfs cur_state
------------------------------------------------
0-5 0
6-11 1
..
..
90-95 15
96-100 16
While setting the _FST.control, the compensation will be at
the last step for cur_state = 16, which will set the _FST.control
to 100.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi/fan_core.c')
-rw-r--r-- | drivers/acpi/fan_core.c | 94 |
1 files changed, 68 insertions, 26 deletions
diff --git a/drivers/acpi/fan_core.c b/drivers/acpi/fan_core.c index 484cee0fb13e..01616ec2e9ac 100644 --- a/drivers/acpi/fan_core.c +++ b/drivers/acpi/fan_core.c @@ -63,20 +63,24 @@ static int fan_get_max_state(struct thermal_cooling_device *cdev, unsigned long struct acpi_device *device = cdev->devdata; struct acpi_fan *fan = acpi_driver_data(device); - if (fan->acpi4) - *state = fan->fps_count - 1; - else + if (fan->acpi4) { + if (fan->fif.fine_grain_ctrl) + *state = 100 / fan->fif.step_size; + else + *state = fan->fps_count - 1; + } else { *state = 1; + } + return 0; } -static int fan_get_state_acpi4(struct acpi_device *device, unsigned long *state) +static int acpi_fan_get_fst(struct acpi_device *device, struct acpi_fan_fst *fst) { struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; - struct acpi_fan *fan = acpi_driver_data(device); union acpi_object *obj; acpi_status status; - int control, i; + int ret = 0; status = acpi_evaluate_object(device->handle, "_FST", NULL, &buffer); if (ACPI_FAILURE(status)) { @@ -89,35 +93,52 @@ static int fan_get_state_acpi4(struct acpi_device *device, unsigned long *state) obj->package.count != 3 || obj->package.elements[1].type != ACPI_TYPE_INTEGER) { dev_err(&device->dev, "Invalid _FST data\n"); - status = -EINVAL; + ret = -EINVAL; goto err; } - control = obj->package.elements[1].integer.value; + fst->revision = obj->package.elements[0].integer.value; + fst->control = obj->package.elements[1].integer.value; + fst->speed = obj->package.elements[2].integer.value; + +err: + kfree(obj); + return ret; +} + +static int fan_get_state_acpi4(struct acpi_device *device, unsigned long *state) +{ + struct acpi_fan *fan = acpi_driver_data(device); + struct acpi_fan_fst fst; + int status, i; + + status = acpi_fan_get_fst(device, &fst); + if (status) + return status; + + if (fan->fif.fine_grain_ctrl) { + /* This control should be same what we set using _FSL by spec */ + if (fst.control > 100) { + dev_dbg(&device->dev, "Invalid control value returned\n"); + goto match_fps; + } + + *state = (int) fst.control / fan->fif.step_size; + return 0; + } + +match_fps: for (i = 0; i < fan->fps_count; i++) { - /* - * When Fine Grain Control is set, return the state - * corresponding to maximum fan->fps[i].control - * value compared to the current speed. Here the - * fan->fps[] is sorted array with increasing speed. - */ - if (fan->fif.fine_grain_ctrl && control < fan->fps[i].control) { - i = (i > 0) ? i - 1 : 0; - break; - } else if (control == fan->fps[i].control) { + if (fst.control == fan->fps[i].control) break; - } } if (i == fan->fps_count) { dev_dbg(&device->dev, "Invalid control value returned\n"); - status = -EINVAL; - goto err; + return -EINVAL; } *state = i; -err: - kfree(obj); return status; } @@ -161,12 +182,27 @@ static int fan_set_state_acpi4(struct acpi_device *device, unsigned long state) { struct acpi_fan *fan = acpi_driver_data(device); acpi_status status; + u64 value = state; + int max_state; - if (state >= fan->fps_count) + if (fan->fif.fine_grain_ctrl) + max_state = 100 / fan->fif.step_size; + else + max_state = fan->fps_count - 1; + + if (state > max_state) return -EINVAL; - status = acpi_execute_simple_method(device->handle, "_FSL", - fan->fps[state].control); + if (fan->fif.fine_grain_ctrl) { + value *= fan->fif.step_size; + /* Spec allows compensate the last step only */ + if (value + fan->fif.step_size > 100) + value = 100; + } else { + value = fan->fps[state].control; + } + + status = acpi_execute_simple_method(device->handle, "_FSL", value); if (ACPI_FAILURE(status)) { dev_dbg(&device->dev, "Failed to set state by _FSL\n"); return -ENODEV; @@ -238,6 +274,12 @@ static int acpi_fan_get_fif(struct acpi_device *device) fan->fif.step_size = fields[2]; fan->fif.low_speed_notification = fields[3]; + /* If there is a bug in step size and set as 0, change to 1 */ + if (!fan->fif.step_size) + fan->fif.step_size = 1; + /* If step size > 9, change to 9 (by spec valid values 1-9) */ + else if (fan->fif.step_size > 9) + fan->fif.step_size = 9; err: kfree(obj); return status; |