linux-kernel - Re: [PATCH v3 05/12] drm/bridge/synopsys: dw-hdmi: don't clobber drvdata

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Date:   Thu, 18 Jan 2018 14:04:08 +0100
From:   Neil Armstrong <narmstrong@...libre.com>
To:     Jernej Skrabec <jernej.skrabec@...l.net>,
        maxime.ripard@...e-electrons.com, airlied@...ux.ie,
        robh+dt@...nel.org, mark.rutland@....com, wens@...e.org,
        architt@...eaurora.org, a.hajda@...sung.com,
        Laurent.pinchart@...asonboard.com
Cc:     mturquette@...libre.com, sboyd@...eaurora.org,
        Jose.Abreu@...opsys.com, dri-devel@...ts.freedesktop.org,
        devicetree@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org, linux-clk@...r.kernel.org,
        linux-sunxi@...glegroups.com, p.zabel@...gutronix.de,
        hjc@...k-chips.com, heiko@...ech.de
Subject: Re: [PATCH v3 05/12] drm/bridge/synopsys: dw-hdmi: don't clobber
 drvdata

On 17/01/2018 21:14, Jernej Skrabec wrote:
> dw_hdmi shouldn't set drvdata since some drivers might need to store
> it's own data there. Rework dw_hdmi in a way to return struct dw_hdmi
> instead to store it in drvdata. This way drivers are responsible to
> store and pass structure when needed.
> 
> Idea was taken from the following commit:
> 8242ecbd597d ("drm/bridge/synopsys: stop clobbering drvdata")
> 
> Cc: p.zabel@...gutronix.de
> Cc: narmstrong@...libre.com
> Cc: Laurent.pinchart@...asonboard.com
> Cc: hjc@...k-chips.com
> Cc: heiko@...ech.de
> Signed-off-by: Jernej Skrabec <jernej.skrabec@...l.net>
> ---
>  drivers/gpu/drm/bridge/synopsys/dw-hdmi.c   | 31 ++++++++++++-----------------
>  drivers/gpu/drm/imx/dw_hdmi-imx.c           | 13 +++++++++---
>  drivers/gpu/drm/meson/meson_dw_hdmi.c       | 14 +++++++++----
>  drivers/gpu/drm/rcar-du/rcar_dw_hdmi.c      | 12 +++++++++--
>  drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c | 13 +++++++++---
>  include/drm/bridge/dw_hdmi.h                | 13 ++++++------
>  6 files changed, 60 insertions(+), 36 deletions(-)
> 

[...]
> diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c b/drivers/gpu/drm/meson/meson_dw_hdmi.c
> index e8c3ef8a94ce..d49af17310c9 100644
> --- a/drivers/gpu/drm/meson/meson_dw_hdmi.c
> +++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c
> @@ -140,6 +140,7 @@ struct meson_dw_hdmi {
>  	struct clk *venci_clk;
>  	struct regulator *hdmi_supply;
>  	u32 irq_stat;
> +	struct dw_hdmi *hdmi;
>  };
>  #define encoder_to_meson_dw_hdmi(x) \
>  	container_of(x, struct meson_dw_hdmi, encoder)
> @@ -878,9 +879,12 @@ static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
>  	dw_plat_data->input_bus_format = MEDIA_BUS_FMT_YUV8_1X24;
>  	dw_plat_data->input_bus_encoding = V4L2_YCBCR_ENC_709;
>  
> -	ret = dw_hdmi_bind(pdev, encoder, &meson_dw_hdmi->dw_plat_data);
> -	if (ret)
> -		return ret;
> +	platform_set_drvdata(pdev, meson_dw_hdmi);
> +
> +	meson_dw_hdmi->hdmi = dw_hdmi_bind(pdev, encoder,
> +					   &meson_dw_hdmi->dw_plat_data);
> +	if (IS_ERR(meson_dw_hdmi->hdmi))
> +		return PTR_ERR(meson_dw_hdmi->hdmi);
>  
>  	DRM_DEBUG_DRIVER("HDMI controller initialized\n");
>  
> @@ -890,7 +894,9 @@ static int meson_dw_hdmi_bind(struct device *dev, struct device *master,
>  static void meson_dw_hdmi_unbind(struct device *dev, struct device *master,
>  				   void *data)
>  {
> -	dw_hdmi_unbind(dev);
> +	struct meson_dw_hdmi *meson_dw_hdmi = dev_get_drvdata(dev);
> +
> +	dw_hdmi_unbind(meson_dw_hdmi->hdmi);
>  }
>  
>  static const struct component_ops meson_dw_hdmi_ops = {

[..]

> diff --git a/include/drm/bridge/dw_hdmi.h b/include/drm/bridge/dw_hdmi.h
> index f3f3f0e1b2d3..dd2a8cf7d20b 100644
> --- a/include/drm/bridge/dw_hdmi.h
> +++ b/include/drm/bridge/dw_hdmi.h
> @@ -143,12 +143,13 @@ struct dw_hdmi_plat_data {
>  			     unsigned long mpixelclock);
>  };
>  
> -int dw_hdmi_probe(struct platform_device *pdev,
> -		  const struct dw_hdmi_plat_data *plat_data);
> -void dw_hdmi_remove(struct platform_device *pdev);
> -void dw_hdmi_unbind(struct device *dev);
> -int dw_hdmi_bind(struct platform_device *pdev, struct drm_encoder *encoder,
> -		 const struct dw_hdmi_plat_data *plat_data);
> +struct dw_hdmi *dw_hdmi_probe(struct platform_device *pdev,
> +			      const struct dw_hdmi_plat_data *plat_data);
> +void dw_hdmi_remove(struct dw_hdmi *hdmi);
> +void dw_hdmi_unbind(struct dw_hdmi *hdmi);
> +struct dw_hdmi *dw_hdmi_bind(struct platform_device *pdev,
> +			     struct drm_encoder *encoder,
> +			     const struct dw_hdmi_plat_data *plat_data);
>  
>  void dw_hdmi_setup_rx_sense(struct device *dev, bool hpd, bool rx_sense);
>  
> 

For meson-drm and dw-hdmi bridge changes :
Acked-by: Neil Armstrong <narmstrong@...libre.com>