Re: [PATCH] drm/bridge: panel: Remove a redundant check on existence of bridge->encoder

[Laurent Pinchart]

Hi Sui,

Thank you for the patch.

On Sat, May 11, 2024 at 10:03:16PM +0800, Sui Jingfeng wrote:
> In panel_bridge_attach(), the check on the existence of bridge->encoder
> has already been done in the implementation of drm_bridge_attach(). And
> it is done before the bridge->funcs->attach hook is called. Hence, it is
> guaranteed that the .encoder member of the struct drm_bridge is not NULL
> when the panel_bridge_attach() is called.
> 
> There is no need to check the existence of bridge->encoder another time
> at the implementation layer, therefore remove the redundant checking codes
> "if (!bridge->encoder) { ... }".
> 
> Signed-off-by: Sui Jingfeng 

Reviewed-by: Laurent Pinchart 

> ---
>  drivers/gpu/drm/bridge/panel.c | 5 -
>  1 file changed, 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/panel.c b/drivers/gpu/drm/bridge/panel.c
> index 7f41525f7a6e..762402dca6dd 100644
> --- a/drivers/gpu/drm/bridge/panel.c
> +++ b/drivers/gpu/drm/bridge/panel.c
> @@ -65,11 +65,6 @@ static int panel_bridge_attach(struct drm_bridge *bridge,
>   if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
>   return 0;
>  
> - if (!bridge->encoder) {
> - DRM_ERROR("Missing encoder\n");
> - return -ENODEV;
> - }
> -
>   drm_connector_helper_add(connector,
>_bridge_connector_helper_funcs);
>  

-- 
Regards,

Laurent Pinchart

[PATCH] drm/bridge: panel: Remove a redundant check on existence of bridge->encoder

[Sui Jingfeng]

In panel_bridge_attach(), the check on the existence of bridge->encoder
has already been done in the implementation of drm_bridge_attach(). And
it is done before the bridge->funcs->attach hook is called. Hence, it is
guaranteed that the .encoder member of the struct drm_bridge is not NULL
when the panel_bridge_attach() is called.

There is no need to check the existence of bridge->encoder another time
at the implementation layer, therefore remove the redundant checking codes
"if (!bridge->encoder) { ... }".

Signed-off-by: Sui Jingfeng 
---
 drivers/gpu/drm/bridge/panel.c | 5 -
 1 file changed, 5 deletions(-)

diff --git a/drivers/gpu/drm/bridge/panel.c b/drivers/gpu/drm/bridge/panel.c
index 7f41525f7a6e..762402dca6dd 100644
--- a/drivers/gpu/drm/bridge/panel.c
+++ b/drivers/gpu/drm/bridge/panel.c
@@ -65,11 +65,6 @@ static int panel_bridge_attach(struct drm_bridge *bridge,
if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)
return 0;
 
-   if (!bridge->encoder) {
-   DRM_ERROR("Missing encoder\n");
-   return -ENODEV;
-   }
-
drm_connector_helper_add(connector,
 _bridge_connector_helper_funcs);
 
-- 
2.43.0