Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Wed, 1 Jul 2020 13:23:03 +0200
From:   Boris Brezillon <boris.brezillon@collabora.com>
To:     Enric Balletbo i Serra <enric.balletbo@collabora.com>
Cc:     linux-kernel@vger.kernel.org,
        Collabora Kernel ML <kernel@collabora.com>,
        narmstrong@baylibre.com, a.hajda@samsung.com,
        laurent.pinchart@ideasonboard.com, matthias.bgg@gmail.com,
        drinkcat@chromium.org, hsinyi@chromium.org,
        Chun-Kuang Hu <chunkuang.hu@kernel.org>,
        Daniel Vetter <daniel@ffwll.ch>,
        David Airlie <airlied@linux.ie>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        dri-devel@lists.freedesktop.org,
        linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org
Subject: Re: [RESEND PATCH 1/3] drm/mediatek: mtk_dpi: Rename bridge to
 next_bridge
Message-ID: <20200701132303.047ea605@collabora.com>
In-Reply-To: <20200518173909.2259259-2-enric.balletbo@collabora.com>
References: <20200518173909.2259259-1-enric.balletbo@collabora.com>
        <20200518173909.2259259-2-enric.balletbo@collabora.com>
Organization: Collabora
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Mon, 18 May 2020 19:39:07 +0200
Enric Balletbo i Serra <enric.balletbo@collabora.com> wrote:

> This is really a cosmetic change just to make a bit more readable the
> code after convert the driver to drm_bridge. The bridge variable name
> will be used by the encoder drm_bridge, and the chained bridge will be
> named next_bridge.
> 
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> Reviewed-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
> ---
> 
>  drivers/gpu/drm/mediatek/mtk_dpi.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediatek/mtk_dpi.c
> index 7fbfa95bab09..7112125dc3d1 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dpi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
> @@ -61,7 +61,7 @@ enum mtk_dpi_out_color_format {
>  struct mtk_dpi {
>  	struct mtk_ddp_comp ddp_comp;
>  	struct drm_encoder encoder;
> -	struct drm_bridge *bridge;
> +	struct drm_bridge *next_bridge;

Did you consider moving the drm_of_find_panel_or_bridge() call to
mtk_dpi_bind() so you can get rid of this field?

This makes we realize there's no refcounting on bridges, which means
the bridge can vanish between the drm_of_find_panel_or_bridge() and
drm_bridge_attach() calls :-/.

>  	void __iomem *regs;
>  	struct device *dev;
>  	struct clk *engine_clk;
> @@ -607,7 +607,7 @@ static int mtk_dpi_bind(struct device *dev, struct device *master, void *data)
>  	/* Currently DPI0 is fixed to be driven by OVL1 */
>  	dpi->encoder.possible_crtcs = BIT(1);
>  
> -	ret = drm_bridge_attach(&dpi->encoder, dpi->bridge, NULL, 0);
> +	ret = drm_bridge_attach(&dpi->encoder, dpi->next_bridge, NULL, 0);
>  	if (ret) {
>  		dev_err(dev, "Failed to attach bridge: %d\n", ret);
>  		goto err_cleanup;
> @@ -747,11 +747,11 @@ static int mtk_dpi_probe(struct platform_device *pdev)
>  	}
>  
>  	ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
> -					  NULL, &dpi->bridge);
> +					  NULL, &dpi->next_bridge);
>  	if (ret)
>  		return ret;
>  
> -	dev_info(dev, "Found bridge node: %pOF\n", dpi->bridge->of_node);
> +	dev_info(dev, "Found bridge node: %pOF\n", dpi->next_bridge->of_node);
>  
>  	comp_id = mtk_ddp_comp_get_id(dev->of_node, MTK_DPI);
>  	if (comp_id < 0) {