Re: [PATCH v2 11/12] drm/bridge: samsung-dsim: samsung_dsim_host_attach: don't use the bridge pointer as an error indicator

[Marek Szyprowski <m.szyprowski@samsung.com>]

On 09.01.2026 08:31, Luca Ceresoli wrote:
> In preparation to handle refcounting of the out_bridge, we need to ensure
> the out_bridge pointer contains either a valid bridge pointer or NULL, not
> an ERR_PTR. Otherwise calls such as drm_bridge_get/put() would try to
> redeference an ERR_PTR.
>
> Stop using IS_ERR(next_bridge) as an indication of an error, and instead
> use the 'ret' integer.
>
> No functional change.
>
> Acked-by: Maxime Ripard <mripard@kernel.org>
> Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
> ---
>   drivers/gpu/drm/bridge/samsung-dsim.c | 9 +++++----
>   1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c
> index 8dd058124e93..afaa63c4d3f7 100644
> --- a/drivers/gpu/drm/bridge/samsung-dsim.c
> +++ b/drivers/gpu/drm/bridge/samsung-dsim.c
> @@ -1891,7 +1891,7 @@ static int samsung_dsim_host_attach(struct mipi_dsi_host *host,
>   	struct device_node *np = dev->of_node;
>   	struct device_node *remote;
>   	struct drm_panel *panel;
> -	int ret;
> +	int ret = 0;
>   
>   	/*
>   	 * Devices can also be child nodes when we also control that device
> @@ -1926,16 +1926,17 @@ static int samsung_dsim_host_attach(struct mipi_dsi_host *host,
>   	panel = of_drm_find_panel(remote);
>   	if (!IS_ERR(panel)) {
>   		next_bridge = devm_drm_panel_bridge_add(dev, panel);
> +		if (IS_ERR(next_bridge))
> +			ret = PTR_ERR(next_bridge);
>   	} else {
>   		next_bridge = of_drm_find_bridge(remote);
>   		if (!next_bridge)
> -			next_bridge = ERR_PTR(-EINVAL);
> +			ret = -EINVAL;
>   	}
>   
>   	of_node_put(remote);
>   
> -	if (IS_ERR(next_bridge)) {
> -		ret = PTR_ERR(next_bridge);
> +	if (ret) {
>   		DRM_DEV_ERROR(dev, "failed to find the bridge: %d\n", ret);
>   		return ret;
>   	}
>
Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland