Message-ID: <26986caf-1245-88f2-60d0-5930c86ea31b@linaro.org>
Date:   Mon, 6 Mar 2023 14:38:37 +0200
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Subject: Re: [PATCH 09/10] drm/msm: use drmm_mode_config_init()
Content-Language: en-GB
To:     Johan Hovold <johan+linaro@kernel.org>,
        Rob Clark <robdclark@gmail.com>,
        Abhinav Kumar <quic_abhinavk@quicinc.com>
Cc:     Sean Paul <sean@poorly.run>, David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>, linux-arm-msm@vger.kernel.org,
        dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org,
        linux-kernel@vger.kernel.org
References: <20230306100722.28485-1-johan+linaro@kernel.org>
 <20230306100722.28485-10-johan+linaro@kernel.org>
From:   Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
In-Reply-To: <20230306100722.28485-10-johan+linaro@kernel.org>
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Precedence: bulk

On 06/03/2023 12:07, Johan Hovold wrote:
> Switch to using drmm_mode_config_init() so that the mode config is
> released when the last reference to the DRM device is dropped rather
> than unconditionally at unbind() (which may be too soon).

This also means that drm_bridge_detach() might be called at some point 
after unbind(), which might be too late.

> 
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
>   drivers/gpu/drm/msm/msm_drv.c | 11 +++++------
>   1 file changed, 5 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> index 73c597565f99..ade17947d1e5 100644
> --- a/drivers/gpu/drm/msm/msm_drv.c
> +++ b/drivers/gpu/drm/msm/msm_drv.c
> @@ -247,8 +247,6 @@ static int msm_drm_uninit(struct device *dev)
>   	if (kms)
>   		msm_disp_snapshot_destroy(ddev);
>   
> -	drm_mode_config_cleanup(ddev);
> -
>   	for (i = 0; i < priv->num_bridges; i++)
>   		drm_bridge_remove(priv->bridges[i]);
>   	priv->num_bridges = 0;
> @@ -454,11 +452,13 @@ static int msm_drm_init(struct device *dev, const struct drm_driver *drv)
>   	might_lock(&priv->lru.lock);
>   	fs_reclaim_release(GFP_KERNEL);
>   
> -	drm_mode_config_init(ddev);
> +	ret = drmm_mode_config_init(ddev);
> +	if (ret)
> +		goto err_destroy_wq;
>   
>   	ret = msm_init_vram(ddev);
>   	if (ret)
> -		goto err_cleanup_mode_config;
> +		goto err_destroy_wq;
>   
>   	/* Bind all our sub-components: */
>   	ret = component_bind_all(dev, ddev);
> @@ -563,8 +563,7 @@ static int msm_drm_init(struct device *dev, const struct drm_driver *drv)
>   
>   err_deinit_vram:
>   	msm_deinit_vram(ddev);
> -err_cleanup_mode_config:
> -	drm_mode_config_cleanup(ddev);
> +err_destroy_wq:
>   	destroy_workqueue(priv->wq);
>   err_put_dev:
>   	drm_dev_put(ddev);

-- 
With best wishes
Dmitry