[PATCH 5.6 032/106] hwmon: (drivetemp) Return -ENODATA for invalid temperatures

From: Greg Kroah-Hartman
Date: Fri May 01 2020 - 09:48:25 EST


From: Guenter Roeck <linux@xxxxxxxxxxxx>

commit ed08ebb7124e90a99420bb913d602907d377d03d upstream.

Holger HoffstÃtte observed that Samsung 850 Pro may return invalid
temperatures for a short period of time after resume. Return -ENODATA
to userspace if this is observed.

Fixes: 5b46903d8bf3 ("hwmon: Driver for disk and solid state drives with temperature sensors")
Reported-by: Holger HoffstÃtte <holger@xxxxxxxxxxxxxxxxxxxxxx>
Cc: Holger HoffstÃtte <holger@xxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/hwmon/drivetemp.c | 6 ++++++
1 file changed, 6 insertions(+)

--- a/drivers/hwmon/drivetemp.c
+++ b/drivers/hwmon/drivetemp.c
@@ -264,12 +264,18 @@ static int drivetemp_get_scttemp(struct
return err;
switch (attr) {
case hwmon_temp_input:
+ if (!temp_is_valid(buf[SCT_STATUS_TEMP]))
+ return -ENODATA;
*val = temp_from_sct(buf[SCT_STATUS_TEMP]);
break;
case hwmon_temp_lowest:
+ if (!temp_is_valid(buf[SCT_STATUS_TEMP_LOWEST]))
+ return -ENODATA;
*val = temp_from_sct(buf[SCT_STATUS_TEMP_LOWEST]);
break;
case hwmon_temp_highest:
+ if (!temp_is_valid(buf[SCT_STATUS_TEMP_HIGHEST]))
+ return -ENODATA;
*val = temp_from_sct(buf[SCT_STATUS_TEMP_HIGHEST]);
break;
default: