Re: [PATCH v1 2/5] watchdog: intel-mid_wdt: Postpone IRQ handler registration till SCU is ready

[Guenter Roeck <linux@roeck-us.net>]

On 1/22/21 4:31 AM, Andy Shevchenko wrote:
> When SCU is not ready and CONFIG_DEBUG_SHIRQ=y we got deferred probe followed
> by fired test IRQ which immediately makes kernel panic. Fix this by delaying
> IRQ handler registration till SCU is ready.
> 
> Fixes: 80ae679b8f86 ("watchdog: intel-mid_wdt: Convert to use new SCU IPC API")
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Acked-by: Linus Walleij <linus.walleij@linaro.org>
> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

> ---
>  drivers/watchdog/intel-mid_wdt.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/watchdog/intel-mid_wdt.c b/drivers/watchdog/intel-mid_wdt.c
> index 1ae03b64ef8b..9b2173f765c8 100644
> --- a/drivers/watchdog/intel-mid_wdt.c
> +++ b/drivers/watchdog/intel-mid_wdt.c
> @@ -154,6 +154,10 @@ static int mid_wdt_probe(struct platform_device *pdev)
>  	watchdog_set_nowayout(wdt_dev, WATCHDOG_NOWAYOUT);
>  	watchdog_set_drvdata(wdt_dev, mid);
>  
> +	mid->scu = devm_intel_scu_ipc_dev_get(dev);
> +	if (!mid->scu)
> +		return -EPROBE_DEFER;
> +
>  	ret = devm_request_irq(dev, pdata->irq, mid_wdt_irq,
>  			       IRQF_SHARED | IRQF_NO_SUSPEND, "watchdog",
>  			       wdt_dev);
> @@ -162,10 +166,6 @@ static int mid_wdt_probe(struct platform_device *pdev)
>  		return ret;
>  	}
>  
> -	mid->scu = devm_intel_scu_ipc_dev_get(dev);
> -	if (!mid->scu)
> -		return -EPROBE_DEFER;
> -
>  	/*
>  	 * The firmware followed by U-Boot leaves the watchdog running
>  	 * with the default threshold which may vary. When we get here
>