From: Eddie James <eajames@linux.ibm.com>
Date: Thu, 29 Apr 2021 15:13:36 +0000 (-0500)
Subject: hwmon: (occ) Fix poll rate limiting
X-Git-Tag: baikal/aarch64/sdk6.1~6623^2~3
X-Git-Url: https://git.baikalelectronics.ru/sdk/?a=commitdiff_plain;h=02a42d200fe9e07fd18b7af4e02ab9b71fe5fcbe;p=kernel.git

hwmon: (occ) Fix poll rate limiting

The poll rate limiter time was initialized at zero. This breaks the
comparison in time_after if jiffies is large. Switch to storing the
next update time rather than the previous time, and initialize the
time when the device is probed.

Fixes: e95ae074e048 ("hwmon (occ): Add sensor types and versions")
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/r/20210429151336.18980-1-eajames@linux.ibm.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---

diff --git a/drivers/hwmon/occ/common.c b/drivers/hwmon/occ/common.c
index f1ac153d0b568..967532afb1c01 100644
--- a/drivers/hwmon/occ/common.c
+++ b/drivers/hwmon/occ/common.c
@@ -217,9 +217,9 @@ int occ_update_response(struct occ *occ)
 		return rc;
 
 	/* limit the maximum rate of polling the OCC */
-	if (time_after(jiffies, occ->last_update + OCC_UPDATE_FREQUENCY)) {
+	if (time_after(jiffies, occ->next_update)) {
 		rc = occ_poll(occ);
-		occ->last_update = jiffies;
+		occ->next_update = jiffies + OCC_UPDATE_FREQUENCY;
 	} else {
 		rc = occ->last_error;
 	}
@@ -1165,6 +1165,7 @@ int occ_setup(struct occ *occ, const char *name)
 		return rc;
 	}
 
+	occ->next_update = jiffies + OCC_UPDATE_FREQUENCY;
 	occ_parse_poll_response(occ);
 
 	rc = occ_setup_sensor_attrs(occ);
diff --git a/drivers/hwmon/occ/common.h b/drivers/hwmon/occ/common.h
index 67e6968b8978e..e6df719770e81 100644
--- a/drivers/hwmon/occ/common.h
+++ b/drivers/hwmon/occ/common.h
@@ -99,7 +99,7 @@ struct occ {
 	u8 poll_cmd_data;		/* to perform OCC poll command */
 	int (*send_cmd)(struct occ *occ, u8 *cmd);
 
-	unsigned long last_update;
+	unsigned long next_update;
 	struct mutex lock;		/* lock OCC access */
 
 	struct device *hwmon;