linux-kernel - Re: [PATCH next] drm: zynqmp_dp: Unlock on error in zynqmp_dp_bridge_atomic

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Message-ID: <20241112052754.GB21062@pendragon.ideasonboard.com>
Date: Tue, 12 Nov 2024 07:27:54 +0200
From: Laurent Pinchart <laurent.pinchart@...asonboard.com>
To: Dan Carpenter <dan.carpenter@...aro.org>
Cc: Sean Anderson <sean.anderson@...ux.dev>,
	Tomi Valkeinen <tomi.valkeinen@...asonboard.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>,
	Michal Simek <michal.simek@....com>,
	dri-devel@...ts.freedesktop.org,
	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	kernel-janitors@...r.kernel.org
Subject: Re: [PATCH next] drm: zynqmp_dp: Unlock on error in
 zynqmp_dp_bridge_atomic_enable()

Hi Dan,

Thank you for the patch.

On Mon, Nov 11, 2024 at 12:06:10PM +0300, Dan Carpenter wrote:
> We added some locking to this function, but accidentally forgot to unlock
> if zynqmp_dp_mode_configure() failed.  Use a guard lock to fix it.
> 
> Fixes: a7d5eeaa57d7 ("drm: zynqmp_dp: Add locking")
> Signed-off-by: Dan Carpenter <dan.carpenter@...aro.org>

Reviewed-by: Laurent Pinchart <laurent.pinchart@...asonboard.com>

Sean, how about replacing all the mutex_lock()/mutex_unlock() calls
you've added in a7d5eeaa57d7 with guards ?

> ---
>  drivers/gpu/drm/xlnx/zynqmp_dp.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c
> index 25c5dc61ee88..0bea908b281e 100644
> --- a/drivers/gpu/drm/xlnx/zynqmp_dp.c
> +++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c
> @@ -1537,7 +1537,7 @@ static void zynqmp_dp_bridge_atomic_enable(struct drm_bridge *bridge,
>  
>  	pm_runtime_get_sync(dp->dev);
>  
> -	mutex_lock(&dp->lock);
> +	guard(mutex)(&dp->lock);
>  	zynqmp_dp_disp_enable(dp, old_bridge_state);
>  
>  	/*
> @@ -1598,7 +1598,6 @@ static void zynqmp_dp_bridge_atomic_enable(struct drm_bridge *bridge,
>  	zynqmp_dp_write(dp, ZYNQMP_DP_SOFTWARE_RESET,
>  			ZYNQMP_DP_SOFTWARE_RESET_ALL);
>  	zynqmp_dp_write(dp, ZYNQMP_DP_MAIN_STREAM_ENABLE, 1);
> -	mutex_unlock(&dp->lock);
>  }
>  
>  static void zynqmp_dp_bridge_atomic_disable(struct drm_bridge *bridge,

-- 
Regards,

Laurent Pinchart