Re: [PATCH] drm/rockchip: dw_hdmi: filter regulator -EPROBE_DEFER error messages

[John Keeping]

On Mon, Sep 26, 2022 at 10:37:52PM +0200, Aurelien Jarno wrote:
> When the avdd-0v9 or avdd-1v8 supply are not yet available, EPROBE_DEFER
> is returned by rockchip_hdmi_parse_dt(). This causes the following error
> message to be printed multiple times:
> 
>     dwhdmi-rockchip fe0a0000.hdmi: [drm:dw_hdmi_rockchip_bind [rockchipdrm]] *ERROR* Unable to parse OF data
> 
> Fix that by not printing the message when rockchip_hdmi_parse_dt()
> returns -EPROBE_DEFER.
> 
> Fixes: ca80c4eb4b01 ("drm/rockchip: dw_hdmi: add regulator support")
> Signed-off-by: Aurelien Jarno <aurelien@xxxxxxxxxxx>
> ---
>  drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c b/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
> index c14f88893868..2f4b8f64cbad 100644
> --- a/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
> +++ b/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
> @@ -565,7 +565,8 @@ static int dw_hdmi_rockchip_bind(struct device *dev, struct device *master,
>  
>  	ret = rockchip_hdmi_parse_dt(hdmi);
>  	if (ret) {
> -		DRM_DEV_ERROR(hdmi->dev, "Unable to parse OF data\n");
> +		if (ret != -EPROBE_DEFER)
> +			DRM_DEV_ERROR(hdmi->dev, "Unable to parse OF data\n");

Can we use dev_err_probe() here?

There's no DRM-specific variant, but that is already widely used across
the DRM subsystem.