watchdog: imx_sc_wdt: Don't disable WDT in suspend

[ Upstream commit 2d9d6d300fb0a4ae4431bb308027ac9385746d42 ]

Parts of the suspend and resume chain is left unprotected if we disable
the WDT here.

>From experiments we can see that the SCU disables and re-enables the WDT
when we enter and leave suspend to ram. By not touching the WDT here we
are protected by the WDT all the way to the SCU.

Signed-off-by: Jonas Blixt <jonas.blixt@actia.se>
CC: Anson Huang <anson.huang@nxp.com>
Fixes: 986857acbc9a ("watchdog: imx_sc: Add i.MX system controller watchdog support")
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20240801121845.1465765-1-jonas.blixt@actia.se
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/watchdog/imx_sc_wdt.c b/drivers/watchdog/imx_sc_wdt.c
index e51fe1b78518f42a25b70fb3755fe93c5f5c9e22..d73076b686d8ca81835b500d76a84ea6f55f6148 100644 (file)
--- a/drivers/watchdog/imx_sc_wdt.c
+++ b/drivers/watchdog/imx_sc_wdt.c
@@ -216,29 +216,6 @@ register_device:
        return devm_watchdog_register_device(dev, wdog);
 }
 
-static int __maybe_unused imx_sc_wdt_suspend(struct device *dev)
-{
-       struct imx_sc_wdt_device *imx_sc_wdd = dev_get_drvdata(dev);
-
-       if (watchdog_active(&imx_sc_wdd->wdd))
-               imx_sc_wdt_stop(&imx_sc_wdd->wdd);
-
-       return 0;
-}
-
-static int __maybe_unused imx_sc_wdt_resume(struct device *dev)
-{
-       struct imx_sc_wdt_device *imx_sc_wdd = dev_get_drvdata(dev);
-
-       if (watchdog_active(&imx_sc_wdd->wdd))
-               imx_sc_wdt_start(&imx_sc_wdd->wdd);
-
-       return 0;
-}
-
-static SIMPLE_DEV_PM_OPS(imx_sc_wdt_pm_ops,
-                        imx_sc_wdt_suspend, imx_sc_wdt_resume);
-
 static const struct of_device_id imx_sc_wdt_dt_ids[] = {
        { .compatible = "fsl,imx-sc-wdt", },
        { /* sentinel */ }
@@ -250,7 +227,6 @@ static struct platform_driver imx_sc_wdt_driver = {
        .driver         = {
                .name   = "imx-sc-wdt",
                .of_match_table = imx_sc_wdt_dt_ids,
-               .pm     = &imx_sc_wdt_pm_ops,
        },
 };
 module_platform_driver(imx_sc_wdt_driver);