Re: [PATCH] ar7: register watchdog driver only if enabled in hardware configuration

[Alexander Clouter <alex@digriz.org.uk>]

Florian Fainelli <florian@openwrt.org> wrote:
>
> This patch checks if the watchdog enable bit is set in the DCL
> register meaning that the hardware watchdog actually works and
> if so, register the ar7_wdt platform_device.
> 
> Signed-off-by: Florian Fainelli <florian@openwrt.org>
> ---
> diff --git a/arch/mips/ar7/platform.c b/arch/mips/ar7/platform.c
> index e2278c0..835f3f0 100644
> --- a/arch/mips/ar7/platform.c
> +++ b/arch/mips/ar7/platform.c
> @@ -503,6 +503,7 @@ static int __init ar7_register_devices(void)
> {
>        u16 chip_id;
>        int res;
> +       u32 *bootcr, val;
> #ifdef CONFIG_SERIAL_8250
>        static struct uart_port uart_port[2];
> 
> @@ -595,7 +596,13 @@ static int __init ar7_register_devices(void)
> 
>        ar7_wdt_res.end = ar7_wdt_res.start + 0x20;
> 
> -       res = platform_device_register(&ar7_wdt);
> +       bootcr = (u32 *)ioremap_nocache(AR7_REGS_DCL, 4);
> +       val = *bootcr;
> +       iounmap(bootcr);
> +
> +       /* Register watchdog only if enabled in hardware */
> +       if (val & AR7_WDT_HW_ENA)
> +               res = platform_device_register(&ar7_wdt);
> 
>        return res;
> }
>
'res' can now return NULL[1].  Solved if you do:
----
int res = -ENODEV;
----

I'm guessing this is the most apprioate?

Cheers

[1] I cannot see the full file annoyingly, it's not in my linux-mips 
	git tree.

-- 
Alexander Clouter
.sigmonster says: It doesn't matter whether you win or lose -- until you lose.