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From: Wolfram Sang <wsa+renesas@sang-engineering.com>
To: linux-watchdog@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org,
	Wolfram Sang <wsa+renesas@sang-engineering.com>
Subject: [PATCH 01/16] watchdog: refactor watchdog_init_timeout
Date: Sun, 14 Apr 2019 12:26:12 +0200
Message-ID: <20190414102627.5564-2-wsa+renesas@sang-engineering.com> (raw)
In-Reply-To: <20190414102627.5564-1-wsa+renesas@sang-engineering.com>

The function is not easy to read and has two problems: a) -EINVAL is
returned when the module parameter is invalid but the DT parameter is
OK, and b) for the module parameter, zero is a valid value but for DT it
is invalid.

Refactor the code to have a the same pattern of checks for the module
parameter and DT. Further ones can be easily added in the future if the
need arises. The above mentioned problems are fixed, too.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
 drivers/watchdog/watchdog_core.c | 33 ++++++++++++++++++---------------
 1 file changed, 18 insertions(+), 15 deletions(-)

diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c
index eb8fa25f8eb2..85c136acc0e9 100644
--- a/drivers/watchdog/watchdog_core.c
+++ b/drivers/watchdog/watchdog_core.c
@@ -104,10 +104,11 @@ static void watchdog_check_min_max_timeout(struct watchdog_device *wdd)
  * Initialize the timeout field of the watchdog_device struct with either the
  * timeout module parameter (if it is valid value) or the timeout-sec property
  * (only if it is a valid value and the timeout_parm is out of bounds).
- * If none of them are valid then we keep the old value (which should normally
- * be the default timeout value).
+ * If none of them are valid or all of them are zero ("don't care") then we keep
+ * the old value (which should normally be the default timeout value).
  *
- * A zero is returned on success and -EINVAL for failure.
+ * A zero is returned on success or -EINVAL if all provided values are out of
+ * bounds.
  */
 int watchdog_init_timeout(struct watchdog_device *wdd,
 				unsigned int timeout_parm, struct device *dev)
@@ -117,22 +118,24 @@ int watchdog_init_timeout(struct watchdog_device *wdd,
 
 	watchdog_check_min_max_timeout(wdd);
 
-	/* try to get the timeout module parameter first */
-	if (!watchdog_timeout_invalid(wdd, timeout_parm) && timeout_parm) {
-		wdd->timeout = timeout_parm;
-		return ret;
-	}
-	if (timeout_parm)
+	/* check the driver supplied value (likely a module parameter) first */
+	if (timeout_parm) {
+		if (!watchdog_timeout_invalid(wdd, timeout_parm)) {
+			wdd->timeout = timeout_parm;
+			return 0;
+		}
 		ret = -EINVAL;
+	}
 
 	/* try to get the timeout_sec property */
-	if (dev == NULL || dev->of_node == NULL)
-		return ret;
-	of_property_read_u32(dev->of_node, "timeout-sec", &t);
-	if (!watchdog_timeout_invalid(wdd, t) && t)
-		wdd->timeout = t;
-	else
+	if (dev && dev->of_node &&
+	    of_property_read_u32(dev->of_node, "timeout-sec", &t) == 0 && t) {
+		if (!watchdog_timeout_invalid(wdd, t)) {
+			wdd->timeout = t;
+			return 0;
+		}
 		ret = -EINVAL;
+	}
 
 	return ret;
 }
-- 
2.11.0


  reply index

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-14 10:26 [PATCH 00/16] watchdog: refactor init_timeout and update users Wolfram Sang
2019-04-14 10:26 ` Wolfram Sang [this message]
2019-04-14 13:25   ` [PATCH 01/16] watchdog: refactor watchdog_init_timeout Guenter Roeck
2019-04-14 13:42     ` Wolfram Sang
2019-04-14 14:03       ` Guenter Roeck
2019-04-15  8:21   ` Sergei Shtylyov
2019-04-14 10:26 ` [PATCH 02/16] watchdog: add error messages when initializing timeout fails Wolfram Sang
2019-04-14 10:26 ` [PATCH 03/16] watchdog: cadence_wdt: drop warning after calling watchdog_init_timeout Wolfram Sang
2019-04-14 10:26 ` [PATCH 04/16] watchdog: cadence_wdt: still probe if user supplied timeout is invalid Wolfram Sang
2019-04-14 10:26 ` [PATCH 05/16] watchdog: ebc-c384_wdt: drop warning after calling watchdog_init_timeout Wolfram Sang
2019-04-14 10:26 ` [PATCH 06/16] watchdog: hpwdt: " Wolfram Sang
2019-04-14 10:26 ` [PATCH 07/16] watchdog: i6300esb: " Wolfram Sang
2019-04-14 10:26 ` [PATCH 08/16] watchdog: imx_sc_wdt: " Wolfram Sang
2019-04-14 10:26 ` [PATCH 09/16] watchdog: ni903x_wdt: " Wolfram Sang
2019-04-14 10:26 ` [PATCH 10/16] watchdog: nic7018_wdt: " Wolfram Sang
2019-04-14 10:26 ` [PATCH 11/16] watchdog: renesas_wdt: " Wolfram Sang
2019-04-14 10:26 ` [PATCH 12/16] watchdog: sp5100_tco: " Wolfram Sang
2019-04-14 10:26 ` [PATCH 13/16] watchdog: st_lpc_wdt: " Wolfram Sang
2019-04-14 10:26 ` [PATCH 14/16] watchdog: stm32_iwdg: " Wolfram Sang
2019-04-14 10:26 ` [PATCH 15/16] watchdog: xen_wdt: " Wolfram Sang
2019-04-14 10:26 ` [PATCH 16/16] watchdog: ziirave_wdt: " Wolfram Sang
2019-04-14 10:30 ` [PATCH 00/16] watchdog: refactor init_timeout and update users Wolfram Sang
2019-04-14 15:41 ` Guenter Roeck

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