Re: [PATCH] irqchip: gic: Don't complain in gic_get_cpumask() if UP system

From: Felipe Balbi <balbi@ti.com>
To: Stephen Boyd <sboyd@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Jason Cooper <jason@lakedaemon.net>,
	<linux-kernel@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>,
	Russell King <rmk+kernel@arm.linux.org.uk>,
	Stefan Agner <stefan@agner.ch>,
	Linux OMAP Mailing List <linux-omap@vger.kernel.org>,
	Tony Lindgren <tony@atomide.com>
Subject: Re: [PATCH] irqchip: gic: Don't complain in gic_get_cpumask() if UP system
Date: Sat, 31 Jan 2015 01:09:39 -0600	[thread overview]
Message-ID: <20150131070939.GA4068@saruman.tx.rr.com> (raw)
In-Reply-To: <1422665010-5854-1-git-send-email-sboyd@codeaurora.org>

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+linux-omap

On Fri, Jan 30, 2015 at 04:43:30PM -0800, Stephen Boyd wrote:
> In a uniprocessor implementation the interrupt processor targets
> registers are read-as-zero/write-ignored (RAZ/WI). Unfortunately
> gic_get_cpumask() will print a critical message saying
> 
>  GIC CPU mask not found - kernel will fail to boot.
> 
> if these registers all read as zero, but there won't actually be
> a problem on uniprocessor systems and the kernel will boot just
> fine. Skip this check if we're running a UP kernel or if we
> detect that the hardware only supports a single processor.
> 

Nice, I'll test this on AM437x on Monday but certainly looks promising:

Acked-by: Felipe Balbi <balbi@ti.com>

> Acked-by: Nicolas Pitre <nico@linaro.org>
> Cc: Russell King <rmk+kernel@arm.linux.org.uk>
> Cc: Stefan Agner <stefan@agner.ch>
> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
> ---
>  drivers/irqchip/irq-gic.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
> index d617ee5a3d8a..1b70e0de0f6e 100644
> --- a/drivers/irqchip/irq-gic.c
> +++ b/drivers/irqchip/irq-gic.c
> @@ -346,7 +346,7 @@ static u8 gic_get_cpumask(struct gic_chip_data *gic)
>  			break;
>  	}
>  
> -	if (!mask)
> +	if (!mask && num_possible_cpus() > 1)
>  		pr_crit("GIC CPU mask not found - kernel will fail to boot.\n");
>  
>  	return mask;
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
> 
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-- 
balbi

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