linux-kernel - Re: [PATCH v3 2/2] drm/panthor: Fix OPP refcnt leaks in devfreq initialisation

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Message-ID: <ZwPfhg0z3T8u8a6_@e110455-lin.cambridge.arm.com>
Date: Mon, 7 Oct 2024 14:17:58 +0100
From: Liviu Dudau <liviu.dudau@....com>
To: Adrián Larumbe <adrian.larumbe@...labora.com>
Cc: Boris Brezillon <boris.brezillon@...labora.com>,
	Rob Herring <robh@...nel.org>, Steven Price <steven.price@....com>,
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
	Maxime Ripard <mripard@...nel.org>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>,
	AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>,
	Grant Likely <grant.likely@...aro.org>,
	Heiko Stuebner <heiko@...ech.de>, kernel@...labora.com,
	dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 2/2] drm/panthor: Fix OPP refcnt leaks in devfreq
 initialisation

On Sat, Oct 05, 2024 at 05:08:53PM +0100, Adrián Larumbe wrote:
> Rearrange lookup of recommended OPP for the Mali GPU device and its refcnt
> decremental to make sure no OPP object leaks happen in the error path.
> 
> Signed-off-by: Adrián Larumbe <adrian.larumbe@...labora.com>
> Fixes: fac9b22df4b1 ("drm/panthor: Add the devfreq logical block")
> Reviewed-by: Steven Price <steven.price@....com>

Reviewed-by: Liviu Dudau <liviu.dudau@....com>

Best regards,
Liviu

> ---
>  drivers/gpu/drm/panthor/panthor_devfreq.c | 17 ++++++++---------
>  1 file changed, 8 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panthor/panthor_devfreq.c b/drivers/gpu/drm/panthor/panthor_devfreq.c
> index 9d0f891b9b53..ecc7a52bd688 100644
> --- a/drivers/gpu/drm/panthor/panthor_devfreq.c
> +++ b/drivers/gpu/drm/panthor/panthor_devfreq.c
> @@ -163,13 +163,6 @@ int panthor_devfreq_init(struct panthor_device *ptdev)
>  
>  	cur_freq = clk_get_rate(ptdev->clks.core);
>  
> -	opp = devfreq_recommended_opp(dev, &cur_freq, 0);
> -	if (IS_ERR(opp))
> -		return PTR_ERR(opp);
> -
> -	panthor_devfreq_profile.initial_freq = cur_freq;
> -	ptdev->current_frequency = cur_freq;
> -
>  	/* Regulator coupling only takes care of synchronizing/balancing voltage
>  	 * updates, but the coupled regulator needs to be enabled manually.
>  	 *
> @@ -200,18 +193,24 @@ int panthor_devfreq_init(struct panthor_device *ptdev)
>  		return ret;
>  	}
>  
> +	opp = devfreq_recommended_opp(dev, &cur_freq, 0);
> +	if (IS_ERR(opp))
> +		return PTR_ERR(opp);
> +
> +	panthor_devfreq_profile.initial_freq = cur_freq;
> +	ptdev->current_frequency = cur_freq;
> +
>  	/*
>  	 * Set the recommend OPP this will enable and configure the regulator
>  	 * if any and will avoid a switch off by regulator_late_cleanup()
>  	 */
>  	ret = dev_pm_opp_set_opp(dev, opp);
> +	dev_pm_opp_put(opp);
>  	if (ret) {
>  		DRM_DEV_ERROR(dev, "Couldn't set recommended OPP\n");
>  		return ret;
>  	}
>  
> -	dev_pm_opp_put(opp);
> -
>  	/* Find the fastest defined rate  */
>  	opp = dev_pm_opp_find_freq_floor(dev, &freq);
>  	if (IS_ERR(opp))
> -- 
> 2.46.2
> 

-- 
====================
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| but they're not |
| giving me the   |
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