Re: [PATCH] drm/stm: ltdc: Silence -EPROBE_DEFER till bridge attached

[yannick Fertre <yannick.fertre@foss.st.com>]

Hi Jagan,

thanks for the patch.

Tested-by: Yannick Fertre <yannick.fertre@foss.st.com>


On 7/4/21 3:59 PM, Jagan Teki wrote:
> As dw-mipi-dsi supported all possible ways to find the DSI
> devices. It can take multiple iterations for ltdc to find
> all components attached to the DSI bridge.
> 
> The current ltdc driver failed to find the endpoint as
> it returned -EINVAL for the first iteration itself. This leads
> to following error:
> 
> [    3.099289] [drm:ltdc_load] *ERROR* init encoder endpoint 0
> 
> So, check the return value and cleanup the encoder only if it's
> not -EPROBE_DEFER. This make all components in the attached DSI
> bridge found properly.
> 
> Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> ---
>   drivers/gpu/drm/stm/ltdc.c | 8 +++++---
>   1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
> index 08b71248044d..95e983d3ffb5 100644
> --- a/drivers/gpu/drm/stm/ltdc.c
> +++ b/drivers/gpu/drm/stm/ltdc.c
> @@ -1122,8 +1122,9 @@ static int ltdc_encoder_init(struct drm_device *ddev, struct drm_bridge *bridge)
>   
>   	ret = drm_bridge_attach(encoder, bridge, NULL, 0);
>   	if (ret) {
> -		drm_encoder_cleanup(encoder);
> -		return -EINVAL;
> +		if (ret != -EPROBE_DEFER)
> +			drm_encoder_cleanup(encoder);
> +		return ret;
>   	}
>   
>   	DRM_DEBUG_DRIVER("Bridge encoder:%d created\n", encoder->base.id);
> @@ -1266,7 +1267,8 @@ int ltdc_load(struct drm_device *ddev)
>   		if (bridge) {
>   			ret = ltdc_encoder_init(ddev, bridge);
>   			if (ret) {
> -				DRM_ERROR("init encoder endpoint %d\n", i);
> +				if (ret != -EPROBE_DEFER)
> +					DRM_ERROR("init encoder endpoint %d\n", i);
>   				goto err;
>   			}
>   		}
> 

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