From 8083034251f1e21271d3849feb0fd74380819f58 Mon Sep 17 00:00:00 2001 From: Alexander Soldatov Date: Wed, 17 Apr 2019 21:03:29 +0300 Subject: hwmon: (occ) Add temp sensor value check The occ driver supports two formats for the temp sensor value. The OCC firmware for P8 supports only the first format, for which no range checking or error processing is performed in the driver. Inspecting the OCC sources for P8 reveals that OCC may send a special value 0xFFFF to indicate that a sensor read timeout has occurred, see https://github.com/open-power/occ/blob/master_p8/src/occ/cmdh/cmdh_fsp_cmds.c#L395 That situation wasn't handled in the driver. This patch adds invalid temp value check for the sensor data format 1 and handles it the same way as it is done for the format 2, where EREMOTEIO is reported for this case. Signed-off-by: Alexander Soldatov Signed-off-by: Alexander Amelkin Reviewed-by: Alexander Amelkin Cc: Edward A. James Cc: Joel Stanley Reviewed-by: Eddie James Signed-off-by: Guenter Roeck --- drivers/hwmon/occ/common.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'drivers/hwmon') diff --git a/drivers/hwmon/occ/common.c b/drivers/hwmon/occ/common.c index 13a6290c8d25..d593517af5c2 100644 --- a/drivers/hwmon/occ/common.c +++ b/drivers/hwmon/occ/common.c @@ -241,6 +241,12 @@ static ssize_t occ_show_temp_1(struct device *dev, val = get_unaligned_be16(&temp->sensor_id); break; case 1: + /* + * If a sensor reading has expired and couldn't be refreshed, + * OCC returns 0xFFFF for that sensor. + */ + if (temp->value == 0xFFFF) + return -EREMOTEIO; val = get_unaligned_be16(&temp->value) * 1000; break; default: -- cgit v1.2.3-55-g7522