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Subject[PATCH v3 04/12] watchdog: s3c2410: Let kernel kick watchdog
Date
When "tmr_atboot" module param is set, the watchdog is started in
driver's probe. In that case, also set WDOG_HW_RUNNING bit to let
watchdog core driver know it's running. This way watchdog core can kick
the watchdog for us (if CONFIG_WATCHDOG_HANDLE_BOOT_ENABLED option is
enabled), until user space takes control.

WDOG_HW_RUNNING bit must be set before registering the watchdog. So the
"tmr_atboot" handling code is moved before watchdog registration, to
avoid performing the same check twice. This is also logical because
WDOG_HW_RUNNING bit makes WDT core expect actually running watchdog.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
---
Changes in v3:
- Added R-b tag by Krzysztof Kozlowski

Changes in v2:
- Added explanation on moving the code block to commit message
- [PATCH 03/12] handles the case when tmr_atboot is present but valid
timeout wasn't found

drivers/watchdog/s3c2410_wdt.c | 26 +++++++++++++++-----------
1 file changed, 15 insertions(+), 11 deletions(-)

diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c
index 00421cf22556..0845c05034a1 100644
--- a/drivers/watchdog/s3c2410_wdt.c
+++ b/drivers/watchdog/s3c2410_wdt.c
@@ -604,6 +604,21 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
wdt->wdt_device.bootstatus = s3c2410wdt_get_bootstatus(wdt);
wdt->wdt_device.parent = dev;

+ /*
+ * If "tmr_atboot" param is non-zero, start the watchdog right now. Also
+ * set WDOG_HW_RUNNING bit, so that watchdog core can kick the watchdog.
+ *
+ * If we're not enabling the watchdog, then ensure it is disabled if it
+ * has been left running from the bootloader or other source.
+ */
+ if (tmr_atboot) {
+ dev_info(dev, "starting watchdog timer\n");
+ s3c2410wdt_start(&wdt->wdt_device);
+ set_bit(WDOG_HW_RUNNING, &wdt->wdt_device.status);
+ } else {
+ s3c2410wdt_stop(&wdt->wdt_device);
+ }
+
ret = watchdog_register_device(&wdt->wdt_device);
if (ret)
goto err_cpufreq;
@@ -612,17 +627,6 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
if (ret < 0)
goto err_unregister;

- if (tmr_atboot) {
- dev_info(dev, "starting watchdog timer\n");
- s3c2410wdt_start(&wdt->wdt_device);
- } else {
- /* if we're not enabling the watchdog, then ensure it is
- * disabled if it has been left running from the bootloader
- * or other source */
-
- s3c2410wdt_stop(&wdt->wdt_device);
- }
-
platform_set_drvdata(pdev, wdt);

/* print out a statement of readiness */
--
2.30.2
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