6.6-stable review patch. If anyone has any objections, please let me know.
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From: Vignesh Raghavendra vigneshr@ti.com
[ Upstream commit c1a6edf3b541e44e78f10bc6024df779715723f1 ]
Call runtime_pm_put*() if watchdog is not already started during probe and re enable it in watchdog start as required.
On K3 SoCs, watchdogs and their corresponding CPUs are under same power-domain, so if the reference count of unused watchdogs aren't dropped, it will lead to CPU hotplug failures as Device Management firmware won't allow to turn off the power-domain due to dangling reference count.
Fixes: 2d63908bdbfb ("watchdog: Add K3 RTI watchdog support") Signed-off-by: Vignesh Raghavendra vigneshr@ti.com Tested-by: Manorit Chawdhry m-chawdhry@ti.com Reviewed-by: Guenter Roeck linux@roeck-us.net Link: https://lore.kernel.org/r/20231213140110.938129-1-vigneshr@ti.com 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 --- drivers/watchdog/rti_wdt.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c index 8e1be7ba0103..9215793a1c81 100644 --- a/drivers/watchdog/rti_wdt.c +++ b/drivers/watchdog/rti_wdt.c @@ -77,6 +77,11 @@ static int rti_wdt_start(struct watchdog_device *wdd) { u32 timer_margin; struct rti_wdt_device *wdt = watchdog_get_drvdata(wdd); + int ret; + + ret = pm_runtime_resume_and_get(wdd->parent); + if (ret) + return ret;
/* set timeout period */ timer_margin = (u64)wdd->timeout * wdt->freq; @@ -343,6 +348,9 @@ static int rti_wdt_probe(struct platform_device *pdev) if (last_ping) watchdog_set_last_hw_keepalive(wdd, last_ping);
+ if (!watchdog_hw_running(wdd)) + pm_runtime_put_sync(&pdev->dev); + return 0;
err_iomap: @@ -357,7 +365,10 @@ static void rti_wdt_remove(struct platform_device *pdev) struct rti_wdt_device *wdt = platform_get_drvdata(pdev);
watchdog_unregister_device(&wdt->wdd); - pm_runtime_put(&pdev->dev); + + if (!pm_runtime_suspended(&pdev->dev)) + pm_runtime_put(&pdev->dev); + pm_runtime_disable(&pdev->dev); }