Commit 62dbe505 authored by Guenter Roeck's avatar Guenter Roeck
Browse files

hwmon: (max6650) Read non-volatile registers only once 



Only tachometer and alarm status registers are modified by the chip.
All other registers only need to be read only once, and reading them
repeatedly does not add any value.

Cc: Jean-Francois Dagenais <jeff.dagenais@gmail.com>
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent e193acb3

drivers/hwmon/max6650.c

+15 −8
Original line number Diff line number Diff line
@@ -162,17 +162,10 @@ static struct max6650_data *max6650_update_device(struct device *dev) 
	mutex_lock(&data->update_lock);



	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {

		data->speed = i2c_smbus_read_byte_data(client,

						       MAX6650_REG_SPEED);

		data->config = i2c_smbus_read_byte_data(client,

							MAX6650_REG_CONFIG);

		for (i = 0; i < data->nr_fans; i++) {

			data->tach[i] = i2c_smbus_read_byte_data(client,

								 tach_reg[i]);

		}

		data->count = i2c_smbus_read_byte_data(client,

							MAX6650_REG_COUNT);

		data->dac = i2c_smbus_read_byte_data(client, MAX6650_REG_DAC);



		/*

		 * Alarms are cleared on read in case the condition that
@@ -421,8 +414,22 @@ static int max6650_init_client(struct max6650_data *data, 
		dev_err(dev, "Config write error, aborting.\n");

		return err;

	}



	data->config = reg;



	reg = i2c_smbus_read_byte_data(client, MAX6650_REG_SPEED);

	if (reg < 0) {

		dev_err(dev, "Failed to read speed register, aborting.\n");

		return reg;

	}

	data->speed = reg;



	reg = i2c_smbus_read_byte_data(client, MAX6650_REG_DAC);

	if (reg < 0) {

		dev_err(dev, "Failed to read DAC register, aborting.\n");

		return reg;

	}

	data->dac = reg;



	reg = i2c_smbus_read_byte_data(client, MAX6650_REG_COUNT);

	if (reg < 0) {

		dev_err(dev, "Failed to read count register, aborting.\n");

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