On 12/05/2014 03:57 AM, Jean Delvare wrote:
Hi Guenter, On Thu, 4 Dec 2014 10:04:10 -0800, Guenter Roeck wrote: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. Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx> --- drivers/hwmon/lm75.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c index f58439b..6753fd9 100644 --- a/drivers/hwmon/lm75.c +++ b/drivers/hwmon/lm75.c @@ -415,6 +415,12 @@ static int lm75_detect(struct i2c_client *new_client, || i2c_smbus_read_byte_data(new_client, 7) != os) 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 */ for (i = 8; i <= 248; i += 40) {Looks reasonable. Reviewed-by: Jean Delvare <jdelvare@xxxxxxx> Did sensors-detect misdetect that chip as an LM75 too, or was the extended detection logic there good enough already?
Hi Jean, sensors-detect is fine. Easy to test -load i2c-stub and see what happens. I assume that is due to the "All registers hold same value" test. Should I use that test instead ? I kind of prefer it. Thanks, Guenter _______________________________________________ lm-sensors mailing list lm-sensors@xxxxxxxxxxxxxx http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
