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Commit 4ad40cc5 authored by Guenter Roeck's avatar Guenter Roeck
Browse files

hwmon: (lm75) Strengthen detect function 



A chip returning 0x00 in all registers is erroneously detected
as LM75. Check hysteresis and temperature limit registers and
abort if both are 0 to reduce the likelyhood for this to happen.

Reviewed-by: default avatarRob Coulson <rob.coulson@gmail.com>
Reviewed-by: default avatarJean Delvare <jdelvare@suse.de>
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent b95579cd

drivers/hwmon/lm75.c

+6 −0
Original line number Original line Diff line number Diff line
@@ -415,6 +415,12 @@ static int lm75_detect(struct i2c_client *new_client, 
		 || i2c_smbus_read_byte_data(new_client, 7) != os)

		 || i2c_smbus_read_byte_data(new_client, 7) != os)

			return -ENODEV;

			return -ENODEV;

	}

	}

	/*

	 * It is very unlikely that this is a LM75 if both

	 * hysteresis and temperature limit registers are 0.

	 */

	if (hyst == 0 && os == 0)

		return -ENODEV;





	/* Addresses cycling */

	/* Addresses cycling */

	for (i = 8; i <= 248; i += 40) {

	for (i = 8; i <= 248; i += 40) {