Re: [PATCH v3 2/3] drm/vc4: dsi: stop using deprecated drmm_of_get_bridge()

[Maíra Canal]

Hi Luca,

On 13/10/26 12:23, Luca Ceresoli wrote:
> drmm_of_get_bridge() is deprecated, switch to
> of_drm_get_bridge_by_endpoint(). As of_drm_get_bridge_by_endpoint() returns
> a refcounted bridge, ensure it is put by using bridge.next_bridge.
>
> drm_panel.h becomes unused, drop the include.
>
> Signed-off-by: Luca Ceresoli <luca.ceresoli@xxxxxxxxxxx>
>
> ---
>
> Changes in v3:
> - fix bridge reference leak in error path
> ---
>   drivers/gpu/drm/vc4/vc4_dsi.c | 17 ++++++++++-------
>   1 file changed, 10 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c
> index 0148f2befed1..675bd0fc1391 100644
> --- a/drivers/gpu/drm/vc4/vc4_dsi.c
> +++ b/drivers/gpu/drm/vc4/vc4_dsi.c
> @@ -35,7 +35,6 @@
>   #include <drm/drm_edid.h>
>   #include <drm/drm_mipi_dsi.h>
>   #include <drm/drm_of.h>
> -#include <drm/drm_panel.h>
>   #include <drm/drm_print.h>
>   #include <drm/drm_probe_helper.h>
>   #include <drm/drm_simple_kms_helper.h>
> @@ -555,7 +554,6 @@ struct vc4_dsi {
>   
>   	struct platform_device *pdev;
>   
> -	struct drm_bridge *out_bridge;
>   	struct drm_bridge bridge;
>   
>   	void __iomem *regs;
> @@ -1165,7 +1163,7 @@ static int vc4_dsi_bridge_attach(struct drm_bridge *bridge,
>   	struct vc4_dsi *dsi = bridge_to_vc4_dsi(bridge);

I believe you can delete *dsi

>   
>   	/* Attach the panel or bridge to the dsi bridge */
> -	return drm_bridge_attach(encoder, dsi->out_bridge,
> +	return drm_bridge_attach(encoder, dsi->bridge.next_bridge,

and use drm_bridge_attach(encoder, bridge->next_bridge, bridge, flags).
Also, I believe the comment is now redundant as panels are just bridges.

Apart from these nits, could you also address Sashiko's feedback?

Best regards,
- Maíra

>   				 &dsi->bridge, flags);
>   }
>   
> @@ -1749,9 +1747,10 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
>   		return ret;
>   	}
>   
> -	dsi->out_bridge = drmm_of_get_bridge(drm, dev->of_node, 0, 0);
> -	if (IS_ERR(dsi->out_bridge))
> -		return PTR_ERR(dsi->out_bridge);
> +	struct drm_bridge *next_bridge __free(drm_bridge_put) =
> +		of_drm_get_bridge_by_endpoint(dev->of_node, 0, 0);
> +	if (IS_ERR(next_bridge))
> +		return PTR_ERR(next_bridge);
>   
>   	/* The esc clock rate is supposed to always be 100Mhz. */
>   	ret = clk_set_rate(dsi->escape_clock, 100 * 1000000);
> @@ -1775,9 +1774,13 @@ static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
>   	if (ret)
>   		return ret;
>   
> +	dsi->bridge.next_bridge = drm_bridge_get(next_bridge);
> +
>   	ret = drm_bridge_attach(encoder, &dsi->bridge, NULL, 0);
> -	if (ret)
> +	if (ret) {
> +		drm_bridge_clear_and_put(&dsi->bridge.next_bridge);
>   		return ret;
> +	}
>   
>   	return 0;
>   }