[PATCH] powerpc/powernv: pr_warn_once on unsupported OPAL_MSG type

[Michael Ellerman]

On Fri, 2015-12-11 at 12:08 +1100, Stewart Smith wrote:
> When running on newer OPAL firmware that supports sending extra
> OPAL_MSG types, we would print a warning on *every* message received.
> 
> This could be a problem for kernels that don't support OPAL_MSG_OCC
> on machines that are running real close to thermal limits and the
> OCC is throttling the chip. For a kernel that is paying attention to
> the message queue, we could get these notifications quite often.
> 
> Conceivably, future message types could also come fairly often,
> and printing that we didn't understand them 10,000 times provides
> no further information than printing them once.
> 
> diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
> index 4296d55e88f3..57cffb80bc36 100644
> --- a/arch/powerpc/platforms/powernv/opal.c
> +++ b/arch/powerpc/platforms/powernv/opal.c
> @@ -278,7 +278,7 @@ static void opal_handle_message(void)
>  
>  	/* Sanity check */
>  	if (type >= OPAL_MSG_TYPE_MAX) {
> -		pr_warning("%s: Unknown message type: %u\n", __func__, type);
> +		pr_warn_once("%s: Unknown message type: %u\n", __func__, type);
>  		return;

This will only print once, even if there are multiple unknown message types,
are we happy with that?

cheers