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Sender: Corey Minyard <tcminyard@gmail.com>
Date:   Tue, 27 Oct 2020 16:03:37 -0500
From:   Corey Minyard <minyard@acm.org>
To:     Tian Tao <tiantao6@hisilicon.com>
Cc:     arnd@arndb.de, gregkh@linuxfoundation.org,
        openipmi-developer@lists.sourceforge.net,
        linux-kernel@vger.kernel.org
Subject: Re: [Openipmi-developer] [PATCH] ipmi_si: replace spin_lock_irqsave
 by spin_lock in hard IRQ
Message-ID: <20201027210337.GM4296@minyard.net>
Reply-To: minyard@acm.org
References: <1602898810-31783-1-git-send-email-tiantao6@hisilicon.com>
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On Sat, Oct 17, 2020 at 09:40:10AM +0800, Tian Tao wrote:
> It is redundant to do irqsave and irqrestore in hardIRQ context.

Are ACPI GPEs run in hardirq context?  I looked around a bit and
couldn't tell.  If not, then I can't take this patch.  Otherwise, it's
ok.

-corey

> 
> Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
> ---
>  drivers/char/ipmi/ipmi_si_intf.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
> index 45546ac..97452a8 100644
> --- a/drivers/char/ipmi/ipmi_si_intf.c
> +++ b/drivers/char/ipmi/ipmi_si_intf.c
> @@ -1116,7 +1116,6 @@ static void smi_timeout(struct timer_list *t)
>  irqreturn_t ipmi_si_irq_handler(int irq, void *data)
>  {
>  	struct smi_info *smi_info = data;
> -	unsigned long   flags;
>  
>  	if (smi_info->io.si_type == SI_BT)
>  		/* We need to clear the IRQ flag for the BT interface. */
> @@ -1124,14 +1123,14 @@ irqreturn_t ipmi_si_irq_handler(int irq, void *data)
>  				     IPMI_BT_INTMASK_CLEAR_IRQ_BIT
>  				     | IPMI_BT_INTMASK_ENABLE_IRQ_BIT);
>  
> -	spin_lock_irqsave(&(smi_info->si_lock), flags);
> +	spin_lock(&(smi_info->si_lock));
>  
>  	smi_inc_stat(smi_info, interrupts);
>  
>  	debug_timestamp("Interrupt");
>  
>  	smi_event_handler(smi_info, 0);
> -	spin_unlock_irqrestore(&(smi_info->si_lock), flags);
> +	spin_unlock(&(smi_info->si_lock));
>  	return IRQ_HANDLED;
>  }
>  
> -- 
> 2.7.4
> 
> 
> 
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