Re: [PATCH v2] drm/mediatek: dsi: Store driver data before invoking mipi_dsi_host_register

[CK Hu (胡俊光)]

On Mon, 2026-02-23 at 14:16 +0000, Luca Leonardo Scorcia wrote:
> External email : Please do not click links or open attachments until you have verified the sender or the content.
> 
> 
> The call to mipi_dsi_host_register triggers a callback to mtk_dsi_bind,
> which uses dev_get_drvdata to retrieve the mtk_dsi struct, so this
> structure needs to be stored inside the driver data before invoking it.
> 
> As drvdata is currently uninitialized it leads to a crash when
> registering the DSI DRM encoder right after acquiring
> the mode_config.idr_mutex, blocking all subsequent DRM operations.
> 

[snip]

> 
>  drivers/gpu/drm/mediatek/mtk_dsi.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index d7726091819c..af4871de9e4c 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -1232,6 +1232,8 @@ static int mtk_dsi_probe(struct platform_device *pdev)
> 
>         dsi->host.ops = &mtk_dsi_ops;
>         dsi->host.dev = dev;
> +       platform_set_drvdata(pdev, dsi);
> +
>         ret = mipi_dsi_host_register(&dsi->host);
>         if (ret < 0)
>                 return dev_err_probe(dev, ret, "Failed to register DSI host\n");
> @@ -1245,8 +1247,6 @@ static int mtk_dsi_probe(struct platform_device *pdev)
> 
>         init_waitqueue_head(&dsi->irq_wait_queue);

I would like all struct dsi setting done before platform_set_drvdata().
So move init_waitqueue_head() before platform_set_drvdata().

Regards,
CK

> 
> -       platform_set_drvdata(pdev, dsi);
> -
>         dsi->bridge.of_node = dev->of_node;
>         dsi->bridge.type = DRM_MODE_CONNECTOR_DSI;
> 
> --
> 2.43.0
>