Re: [PATCH] drm/panel-simple: take i2c adapter module reference

[Neil Armstrong <neil.armstrong@linaro.org>]

On 7/16/26 15:23, Johan Hovold wrote:
> The i2c subsystem currently blocks during adapter deregistration
> whenever there are consumers holding a reference.
> 
> Switch to using of_get_i2c_adapter_by_node() which also takes a
> reference to the adapter module so that an attempt to unload the module
> while in use fails gracefully instead of blocking uninterruptibly.
> 
> Signed-off-by: Johan Hovold <johan@kernel.org>
> ---
>   drivers/gpu/drm/panel/panel-simple.c | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
> index c09bf3db5e78..f58e83aa4ebe 100644
> --- a/drivers/gpu/drm/panel/panel-simple.c
> +++ b/drivers/gpu/drm/panel/panel-simple.c
> @@ -701,7 +701,7 @@ static struct panel_simple *panel_simple_probe(struct device *dev)
>   
>   	ddc = of_parse_phandle(dev->of_node, "ddc-i2c-bus", 0);
>   	if (ddc) {
> -		panel->ddc = of_find_i2c_adapter_by_node(ddc);
> +		panel->ddc = of_get_i2c_adapter_by_node(ddc);
>   		of_node_put(ddc);
>   
>   		if (!panel->ddc)
> @@ -746,7 +746,7 @@ static struct panel_simple *panel_simple_probe(struct device *dev)
>   	pm_runtime_disable(dev);
>   free_ddc:
>   	if (panel->ddc)
> -		put_device(&panel->ddc->dev);
> +		i2c_put_adapter(panel->ddc);
>   
>   	return ERR_PTR(err);
>   }
> @@ -791,7 +791,7 @@ static void panel_simple_remove(struct device *dev)
>   	pm_runtime_dont_use_autosuspend(dev);
>   	pm_runtime_disable(dev);
>   	if (panel->ddc)
> -		put_device(&panel->ddc->dev);
> +		i2c_put_adapter(panel->ddc);
>   }
>   
>   static const struct drm_display_mode ampire_am_1280800n3tzqw_t00h_mode = {

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>

Thanks,
Neil