linux-kernel - Re: [PATCH] firmware: arm_sdei: fix wrong of_node

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Message-ID: <08d6b9e6-7aa0-9342-193b-1ce6e0417f77@arm.com>
Date:   Fri, 30 Nov 2018 18:31:13 +0000
From:   James Morse <james.morse@....com>
To:     Nicolas Saenz Julienne <nsaenzjulienne@...e.de>
Cc:     linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] firmware: arm_sdei: fix wrong of_node_put() in init
 function

Hi Nicolas,

On 26/11/2018 12:15, Nicolas Saenz Julienne wrote:
> After finding a "firmware" dt node arm_sdei tries to match it's
> compatible string with it. To do so it's calling of_find_matching_node()
> which already takes care of decreasing the refcount on the "firmware"
> node. We are then incorrectly decreasing the refcount on that node
> again.
> 
> This patch removes the unwarranted call to of_node_put().
> 
> Fixes: ad6eb31ef903 ("firmware: arm_sdei: Add driver for Software Delegated Exceptions")
> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@...e.de>


Thanks!, I agree this is unwarranted.
Is there a tool that picks these up? I remember sparse giving me a headache, but
I don't remember this one... I probably cargo-culted it from somewhere else.

Acked-by: James Morse <james.morse@....com>


Thanks,

James


> ---
>  drivers/firmware/arm_sdei.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/firmware/arm_sdei.c b/drivers/firmware/arm_sdei.c
> index 1ea71640fdc2..dffb47c6b480 100644
> --- a/drivers/firmware/arm_sdei.c
> +++ b/drivers/firmware/arm_sdei.c
> @@ -1017,7 +1017,6 @@ static bool __init sdei_present_dt(void)
>  		return false;
>  
>  	np = of_find_matching_node(fw_np, sdei_of_match);
> -	of_node_put(fw_np);
>  	if (!np)
>  		return false;
>  
>