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From:   Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Date:   Wed, 11 May 2022 03:22:19 +0300
Message-ID: <CAA8EJpqBnR_-YaNj-hc6fjfeRX-aTBhuzCFKg77QEyANu37cnA@mail.gmail.com>
Subject: Re: [PATCH v3 3/4] drm/bridge: Add devm_drm_bridge_add()
To:     Douglas Anderson <dianders@chromium.org>
Cc:     dri-devel@lists.freedesktop.org,
        Hsin-Yi Wang <hsinyi@chromium.org>,
        Abhinav Kumar <quic_abhinavk@quicinc.com>,
        Philip Chen <philipchen@chromium.org>,
        Sankeerth Billakanti <quic_sbillaka@quicinc.com>,
        Robert Foss <robert.foss@linaro.org>,
        freedreno@lists.freedesktop.org, linux-arm-msm@vger.kernel.org,
        Stephen Boyd <swboyd@chromium.org>,
        Daniel Vetter <daniel@ffwll.ch>,
        David Airlie <airlied@linux.ie>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Maxime Ripard <mripard@kernel.org>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        linux-kernel@vger.kernel.org
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Precedence: bulk

On Tue, 10 May 2022 at 22:30, Douglas Anderson <dianders@chromium.org> wrote:
>
> This adds a devm managed version of drm_bridge_add(). Like other
> "devm" function listed in drm_bridge.h, this function takes an
> explicit "dev" to use for the lifetime management. A few notes:
> * In general we have a "struct device" for bridges that makes a good
>   candidate for where the lifetime matches exactly what we want.
> * The "bridge->dev->dev" device appears to be the encoder
>   device. That's not the right device to use for lifetime management.
>
> Suggested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Signed-off-by: Douglas Anderson <dianders@chromium.org>

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

> ---
>
> Changes in v3:
> - Patch ("drm/bridge: Add devm_drm_bridge_add()") new for v3.
>
>  drivers/gpu/drm/drm_bridge.c | 23 +++++++++++++++++++++++
>  include/drm/drm_bridge.h     |  1 +
>  2 files changed, 24 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
> index c96847fc0ebc..e275b4ca344b 100644
> --- a/drivers/gpu/drm/drm_bridge.c
> +++ b/drivers/gpu/drm/drm_bridge.c
> @@ -170,6 +170,29 @@ void drm_bridge_add(struct drm_bridge *bridge)
>  }
>  EXPORT_SYMBOL(drm_bridge_add);
>
> +static void drm_bridge_remove_void(void *bridge)
> +{
> +       drm_bridge_remove(bridge);
> +}
> +
> +/**
> + * devm_drm_bridge_add - devm managed version of drm_bridge_add()
> + *
> + * @dev: device to tie the bridge lifetime to
> + * @bridge: bridge control structure
> + *
> + * This is the managed version of drm_bridge_add() which automatically
> + * calls drm_bridge_remove() when @dev is unbound.
> + *
> + * Return: 0 if no error or negative error code.
> + */
> +int devm_drm_bridge_add(struct device *dev, struct drm_bridge *bridge)
> +{
> +       drm_bridge_add(bridge);
> +       return devm_add_action_or_reset(dev, drm_bridge_remove_void, bridge);
> +}
> +EXPORT_SYMBOL(devm_drm_bridge_add);
> +
>  /**
>   * drm_bridge_remove - remove the given bridge from the global bridge list
>   *
> diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
> index f27b4060faa2..42aec8612f37 100644
> --- a/include/drm/drm_bridge.h
> +++ b/include/drm/drm_bridge.h
> @@ -796,6 +796,7 @@ drm_priv_to_bridge(struct drm_private_obj *priv)
>  }
>
>  void drm_bridge_add(struct drm_bridge *bridge);
> +int devm_drm_bridge_add(struct device *dev, struct drm_bridge *bridge);
>  void drm_bridge_remove(struct drm_bridge *bridge);
>  int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
>                       struct drm_bridge *previous,
> --
> 2.36.0.550.gb090851708-goog
>


--
With best wishes
Dmitry