path: root/drivers/watchdog
diff options
authorMartin Kaiser <martin@kaiser.cx>2018-01-01 18:26:47 +0100
committerWim Van Sebroeck <wim@iguana.be>2018-01-21 12:44:58 +0100
commit0be267255cef64e1c58475baa7b25568355a3816 (patch)
tree42446ccbad62cc19f04213eb4b479bb4ba739dbf /drivers/watchdog
parent38a1222ae4f364d5bd5221fe305dbb0889f45d15 (diff)
watchdog: imx2_wdt: restore previous timeout after suspend+resume
When the watchdog device is suspended, its timeout is set to the maximum value. During resume, the previously set timeout should be restored. This does not work at the moment. The suspend function calls imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME); and resume reverts this by calling imx2_wdt_set_timeout(wdog, wdog->timeout); However, imx2_wdt_set_timeout() updates wdog->timeout. Therefore, wdog->timeout is set to IMX2_WDT_MAX_TIME when we enter the resume function. Fix this by adding a new function __imx2_wdt_set_timeout() which only updates the hardware settings. imx2_wdt_set_timeout() now calls __imx2_wdt_set_timeout() and then saves the new timeout to wdog->timeout. During suspend, we call __imx2_wdt_set_timeout() directly so that wdog->timeout won't be updated and we can restore the previous value during resume. This approach makes wdog->timeout different from the actual setting in the hardware which is usually not a good thing. However, the two differ only while we're suspended and no kernel code is running, so it should be ok in this case. Signed-off-by: Martin Kaiser <martin@kaiser.cx> Cc: stable@vger.kernel.org Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Diffstat (limited to 'drivers/watchdog')
1 files changed, 15 insertions, 5 deletions
diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c
index 4874b0f18650..518dfa1047cb 100644
--- a/drivers/watchdog/imx2_wdt.c
+++ b/drivers/watchdog/imx2_wdt.c
@@ -169,15 +169,21 @@ static int imx2_wdt_ping(struct watchdog_device *wdog)
return 0;
-static int imx2_wdt_set_timeout(struct watchdog_device *wdog,
- unsigned int new_timeout)
+static void __imx2_wdt_set_timeout(struct watchdog_device *wdog,
+ unsigned int new_timeout)
struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
- wdog->timeout = new_timeout;
regmap_update_bits(wdev->regmap, IMX2_WDT_WCR, IMX2_WDT_WCR_WT,
+static int imx2_wdt_set_timeout(struct watchdog_device *wdog,
+ unsigned int new_timeout)
+ __imx2_wdt_set_timeout(wdog, new_timeout);
+ wdog->timeout = new_timeout;
return 0;
@@ -371,7 +377,11 @@ static int imx2_wdt_suspend(struct device *dev)
/* The watchdog IP block is running */
if (imx2_wdt_is_running(wdev)) {
- imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME);
+ /*
+ * Don't update wdog->timeout, we'll restore the current value
+ * during resume.
+ */
+ __imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME);

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