linux-kernel - Re: [PATCH v2 4/7] mfd: hi6421-spmi-pmic: Use generic_handle_irq

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Message-ID: <YfgGG0v/zhQp41tr@google.com>
Date:   Mon, 31 Jan 2022 15:54:03 +0000
From:   Lee Jones <lee.jones@...aro.org>
To:     Sebastian Andrzej Siewior <bigeasy@...utronix.de>
Cc:     greybus-dev@...ts.linaro.org, linux-i2c@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-staging@...ts.linux.dev,
        linux-usb@...r.kernel.org, netdev@...r.kernel.org,
        "David S. Miller" <davem@...emloft.net>,
        Alex Elder <elder@...nel.org>, Arnd Bergmann <arnd@...db.de>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Hans de Goede <hdegoede@...hat.com>,
        Jakub Kicinski <kuba@...nel.org>,
        Johan Hovold <johan@...nel.org>,
        Rui Miguel Silva <rmfrfs@...il.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        UNGLinuxDriver@...rochip.com, Wolfram Sang <wsa@...nel.org>,
        Woojung Huh <woojung.huh@...rochip.com>
Subject: Re: [PATCH v2 4/7] mfd: hi6421-spmi-pmic: Use
 generic_handle_irq_safe().

On Mon, 31 Jan 2022, Sebastian Andrzej Siewior wrote:

> generic_handle_irq() is invoked from a regular interrupt service
> routine. This handler will become a forced-threaded handler on
> PREEMPT_RT and will be invoked with enabled interrupts. The
> generic_handle_irq() must be invoked with disabled interrupts in order
> to avoid deadlocks.
> 
> Instead of manually disabling interrupts before invoking use
> generic_handle_irq_safe() which can be invoked with enabled and disabled
> interrupts.
> 
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@...utronix.de>
> ---
>  drivers/misc/hi6421v600-irq.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)

The subject line should be "misc".

> diff --git a/drivers/misc/hi6421v600-irq.c b/drivers/misc/hi6421v600-irq.c
> index 1c763796cf1fa..caa3de37698b0 100644
> --- a/drivers/misc/hi6421v600-irq.c
> +++ b/drivers/misc/hi6421v600-irq.c
> @@ -117,8 +117,8 @@ static irqreturn_t hi6421v600_irq_handler(int irq, void *__priv)
>  			 * If both powerkey down and up IRQs are received,
>  			 * handle them at the right order
>  			 */
> -			generic_handle_irq(priv->irqs[POWERKEY_DOWN]);
> -			generic_handle_irq(priv->irqs[POWERKEY_UP]);
> +			generic_handle_irq_safe(priv->irqs[POWERKEY_DOWN]);
> +			generic_handle_irq_safe(priv->irqs[POWERKEY_UP]);
>  			pending &= ~HISI_IRQ_POWERKEY_UP_DOWN;
>  		}
>  
> @@ -126,7 +126,7 @@ static irqreturn_t hi6421v600_irq_handler(int irq, void *__priv)
>  			continue;
>  
>  		for_each_set_bit(offset, &pending, BITS_PER_BYTE) {
> -			generic_handle_irq(priv->irqs[offset + i * BITS_PER_BYTE]);
> +			generic_handle_irq_safe(priv->irqs[offset + i * BITS_PER_BYTE]);
>  		}
>  	}
>  

-- 
Lee Jones [李琼斯]
Principal Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
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