hwmon: (pmbus) Improve auto-detection of temperature status register

It is possible that a PMBus device supports the READ_TEMPERATURE2 and/or
READ_TEMPERATURE3 registers but does not support READ_TEMPERATURE1.
Improve temperature status register detection to address this condition.

Reported-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Cc: stable@kernel.org # 2.6.39+

1 files changed, 6 insertions, 5 deletions

diff --git a/drivers/hwmon/pmbus.c b/drivers/hwmon/pmbus.c
index 931d940923a..9b1f0c37ef7 100644
--- a/drivers/hwmon/pmbus.c
+++ b/drivers/hwmon/pmbus.c
@@ -59,16 +59,17 @@ static void pmbus_find_sensor_groups(struct i2c_client *client,
                 if (pmbus_check_byte_register(client, 0, PMBUS_STATUS_FAN_34))
                         info->func[0] |= PMBUS_HAVE_STATUS_FAN34;
         }
-        if (pmbus_check_word_register(client, 0, PMBUS_READ_TEMPERATURE_1)) {
+        if (pmbus_check_word_register(client, 0, PMBUS_READ_TEMPERATURE_1))
                 info->func[0] |= PMBUS_HAVE_TEMP;
-                if (pmbus_check_byte_register(client, 0,
-                                              PMBUS_STATUS_TEMPERATURE))
-                        info->func[0] |= PMBUS_HAVE_STATUS_TEMP;
-        }
         if (pmbus_check_word_register(client, 0, PMBUS_READ_TEMPERATURE_2))
                 info->func[0] |= PMBUS_HAVE_TEMP2;
         if (pmbus_check_word_register(client, 0, PMBUS_READ_TEMPERATURE_3))
                 info->func[0] |= PMBUS_HAVE_TEMP3;
+        if (info->func[0] & (PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2
+                             | PMBUS_HAVE_TEMP3)
+            && pmbus_check_byte_register(client, 0,
+                                         PMBUS_STATUS_TEMPERATURE))
+                        info->func[0] |= PMBUS_HAVE_STATUS_TEMP;
 
         /* Sensors detected on all pages */
         for (page = 0; page < info->pages; page++) {