Re: [PATCH v3 1/2] watchdog: dw_wdt: add stop watchdog operation

From: Guenter Roeck
Date: Tue Sep 26 2017 - 03:06:55 EST


On 09/25/2017 10:17 PM, Oleksij Rempel wrote:
Hi,

On 25.09.2017 18:16, Guenter Roeck wrote:
On Mon, Sep 25, 2017 at 07:25:30AM +0200, Oleksij Rempel wrote:
From: Steffen Trumtrar <s.trumtrar@xxxxxxxxxxxxxx>

The only way of stopping the watchdog is by resetting it.
Add the watchdog op for stopping the device and reset if
a reset line is provided.

Signed-off-by: Steffen Trumtrar <s.trumtrar@xxxxxxxxxxxxxx>
Signed-off-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
Cc: Wim Van Sebroeck <wim@xxxxxxxxx>
Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
Cc: linux-watchdog@xxxxxxxxxxxxxxx
---

changes v3:
 - don't return error if rst is not present and set WDOG_HW_RUNNING bit
ÂÂÂ to notify watchdog core.

changes v2:
 - test if dw_wdt->rst is NULL instead of IS_ERR

 drivers/watchdog/dw_wdt.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c
index 36be987ff9ef..6cc56b18ee52 100644
--- a/drivers/watchdog/dw_wdt.c
+++ b/drivers/watchdog/dw_wdt.c
@@ -135,6 +135,21 @@ static int dw_wdt_start(struct watchdog_device *wdd)
ÂÂÂÂÂ return 0;
 }
+static int dw_wdt_stop(struct watchdog_device *wdd)
+{
+ÂÂÂ struct dw_wdt *dw_wdt = to_dw_wdt(wdd);
+
+ÂÂÂ if (!dw_wdt->rst) {
+ÂÂÂÂÂÂÂ set_bit(WDOG_HW_RUNNING, &wdd->status);

Setting WDOG_HW_RUNNING should be dropped from dw_wdt_start().

you mean, this patch is OK, and i need to provide one more which is removing WDOG_HW_RUNNING from dw_wdt_start(). Correct?


No. You are providing a stop function, thus the start function should not set the flag.

Guenter