Re: [PATCH 2/2] irqchip/armada-370-xp: Do not allow mapping IRQ 0 and 1

From: Marc Zyngier <maz@kernel.org>
To: "Pali Rohár" <pali@kernel.org>
Cc: Andrew Lunn <andrew@lunn.ch>,
	Gregory Clement <gregory.clement@bootlin.com>,
	Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] irqchip/armada-370-xp: Do not allow mapping IRQ 0 and 1
Date: Fri, 06 May 2022 12:22:33 +0100	[thread overview]
Message-ID: <87r1567vnq.wl-maz@kernel.org> (raw)
In-Reply-To: <20220425113706.29310-2-pali@kernel.org>

On Mon, 25 Apr 2022 12:37:06 +0100,
Pali Rohár <pali@kernel.org> wrote:
> 
> IRQs 0 and 1 cannot be mapped, they are handled internally by this driver
> and this driver does not call generic_handle_domain_irq() for these IRQs.
> So do not allow mapping these IRQs and correctly propagate error from the
> .irq_map callback.
> 
> Signed-off-by: Pali Rohár <pali@kernel.org>
> Cc: stable@vger.kernel.org
> ---
>  drivers/irqchip/irq-armada-370-xp.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/irqchip/irq-armada-370-xp.c b/drivers/irqchip/irq-armada-370-xp.c
> index 1120084cba09..ebd76ea1c69b 100644
> --- a/drivers/irqchip/irq-armada-370-xp.c
> +++ b/drivers/irqchip/irq-armada-370-xp.c
> @@ -546,6 +546,10 @@ static struct irq_chip armada_370_xp_irq_chip = {
>  static int armada_370_xp_mpic_irq_map(struct irq_domain *h,
>  				      unsigned int virq, irq_hw_number_t hw)
>  {
> +	/* IRQs 0 and 1 cannot be mapped, they are handled internally */
> +	if (hw <= 1)
> +		return -EINVAL;
> +
>  	armada_370_xp_irq_mask(irq_get_irq_data(virq));
>  	if (!is_percpu_irq(hw))
>  		writel(hw, per_cpu_int_base +
> -- 
> 2.20.1
> 
> 

Given that this is completely academic and obviously doesn't affect
anyone, I have removed the Cc: stable from the patch when applying it.

	M.

-- 
Without deviation from the norm, progress is not possible.

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