Re: [PATCH v3 1/2] hwmon: (dell-smm) Add support for fanX_min, fanX_max and fanX_target

Armin Wolf <W_Armin@xxxxxx> · Sat, 16 Oct 2021 23:25:42 +0200

Am 13.10.21 um 20:51 schrieb Guenter Roeck:
On Mon, Sep 27, 2021 at 12:10:43AM +0200, W_Armin@xxxxxx wrote:
From: Armin Wolf <W_Armin@xxxxxx>

The nominal speed of each fan can be obtained with
i8k_get_fan_nominal_speed(), however the result is not available
from userspace.
Change that by adding fanX_min, fanX_max and fanX_target attributes.
All are RO since fan control happens over pwm.

Tested on a Dell Inspiron 3505 and a Dell Latitude C600.

Signed-off-by: Armin Wolf <W_Armin@xxxxxx>
Reviewed-by: Pali Rohár <pali@xxxxxxxxxx>
Applied.

Thanks,
Guenter

---
  Documentation/hwmon/dell-smm-hwmon.rst |  3 ++
  drivers/hwmon/dell-smm-hwmon.c         | 61 +++++++++++++++++++++++---
  2 files changed, 58 insertions(+), 6 deletions(-)

--
2.20.1

diff --git a/Documentation/hwmon/dell-smm-hwmon.rst b/Documentation/hwmon/dell-smm-hwmon.rst
index 3bf77a5df995..beec88491171 100644
--- a/Documentation/hwmon/dell-smm-hwmon.rst
+++ b/Documentation/hwmon/dell-smm-hwmon.rst
@@ -34,6 +34,9 @@ Name				Perm	Description
  =============================== ======= =======================================
  fan[1-3]_input                  RO      Fan speed in RPM.
  fan[1-3]_label                  RO      Fan label.
+fan[1-3]_min                    RO      Minimal Fan speed in RPM
+fan[1-3]_max                    RO      Maximal Fan speed in RPM
+fan[1-3]_target                 RO      Expected Fan speed in RPM
  pwm[1-3]                        RW      Control the fan PWM duty-cycle.
  pwm1_enable                     WO      Enable or disable automatic BIOS fan
                                          control (not supported on all laptops,
diff --git a/drivers/hwmon/dell-smm-hwmon.c b/drivers/hwmon/dell-smm-hwmon.c
index 774c1b0715d9..476f2a74bd8c 100644
--- a/drivers/hwmon/dell-smm-hwmon.c
+++ b/drivers/hwmon/dell-smm-hwmon.c
@@ -76,6 +76,7 @@ struct dell_smm_data {
  	int temp_type[DELL_SMM_NO_TEMP];
  	bool fan[DELL_SMM_NO_FANS];
  	int fan_type[DELL_SMM_NO_FANS];
+	int *fan_nominal_speed[DELL_SMM_NO_FANS];
  };

  MODULE_AUTHOR("Massimo Dal Zotto (dz@xxxxxxxxxx)");
@@ -673,6 +674,13 @@ static umode_t dell_smm_is_visible(const void *drvdata, enum hwmon_sensor_types
  			if (data->fan[channel] && !data->disallow_fan_type_call)
  				return 0444;

+			break;
+		case hwmon_fan_min:
+		case hwmon_fan_max:
+		case hwmon_fan_target:
+			if (data->fan_nominal_speed[channel])
+				return 0444;
+
  			break;
  		default:
  			break;
@@ -740,6 +748,25 @@ static int dell_smm_read(struct device *dev, enum hwmon_sensor_types type, u32 a

  			*val = ret;

+			return 0;
+		case hwmon_fan_min:
+			*val = data->fan_nominal_speed[channel][0];
+
+			return 0;
+		case hwmon_fan_max:
+			*val = data->fan_nominal_speed[channel][data->i8k_fan_max];
+
+			return 0;
+		case hwmon_fan_target:
+			ret = i8k_get_fan_status(data, channel);
+			if (ret < 0)
+				return ret;
+
+			if (ret > data->i8k_fan_max)
+				ret = data->i8k_fan_max;
+
+			*val = data->fan_nominal_speed[channel][ret];
+
  			return 0;
  		default:
  			break;
@@ -889,9 +916,12 @@ static const struct hwmon_channel_info *dell_smm_info[] = {
  			   HWMON_T_INPUT | HWMON_T_LABEL
  			   ),
  	HWMON_CHANNEL_INFO(fan,
-			   HWMON_F_INPUT | HWMON_F_LABEL,
-			   HWMON_F_INPUT | HWMON_F_LABEL,
-			   HWMON_F_INPUT | HWMON_F_LABEL
+			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_MIN | HWMON_F_MAX |
+			   HWMON_F_TARGET,
+			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_MIN | HWMON_F_MAX |
+			   HWMON_F_TARGET,
+			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_MIN | HWMON_F_MAX |
+			   HWMON_F_TARGET
  			   ),
  	HWMON_CHANNEL_INFO(pwm,
  			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
@@ -910,7 +940,7 @@ static int __init dell_smm_init_hwmon(struct device *dev)
  {
  	struct dell_smm_data *data = dev_get_drvdata(dev);
  	struct device *dell_smm_hwmon_dev;
-	int i, err;
+	int i, state, err;

  	for (i = 0; i < DELL_SMM_NO_TEMP; i++) {
  		data->temp_type[i] = i8k_get_temp_type(i);
@@ -926,8 +956,27 @@ static int __init dell_smm_init_hwmon(struct device *dev)
  		err = i8k_get_fan_status(data, i);
  		if (err < 0)
  			err = i8k_get_fan_type(data, i);
-		if (err >= 0)
-			data->fan[i] = true;
+
+		if (err < 0)
+			continue;
+
+		data->fan[i] = true;
+		data->fan_nominal_speed[i] = devm_kmalloc_array(dev, data->i8k_fan_max + 1,
+								sizeof(*data->fan_nominal_speed[i]),
+								GFP_KERNEL);
+		if (!data->fan_nominal_speed[i])
+			continue;
+
+		for (state = 0; state <= data->i8k_fan_max; state++) {
+			err = i8k_get_fan_nominal_speed(data, i, state);
+			if (err < 0) {
+				/* Mark nominal speed table as invalid in case of error */
+				devm_kfree(dev, data->fan_nominal_speed[i]);
+				data->fan_nominal_speed[i] = NULL;
+				break;
+			}
+			data->fan_nominal_speed[i][state] = err;
+		}
  	}

  	dell_smm_hwmon_dev = devm_hwmon_device_register_with_info(dev, "dell_smm", data,
After looking at hwmon-next today, i noticed that this patch was
apparently removed.
Is there a issue with this patch causing the revert?







