Thread (5 messages) 5 messages, 3 authors, 2021-09-22

Re: [PATCH][next] drm/rockchip: Remove redundant assignment of pointer connector

From: Alex Bee <hidden>
Date: 2021-09-22 17:31:52
Also in: dri-devel, kernel-janitors, linux-rockchip, lkml

Hi Heiko,

Am 22.09.21 um 18:45 schrieb Heiko Stübner:
Hi Alex,

Am Mittwoch, 22. September 2021, 18:35:38 CEST schrieb Alex Bee:
quoted
Hi Colin,
Am 22.09.21 um 13:24 schrieb Colin King:
quoted
From: Colin Ian King <redacted>

The pointer connector is being assigned a value that is never
read, it is being updated immediately afterwards. The assignment
is redundant and can be removed.
The pointer to the connector is used in rockchip_rgb_fini for
drm_connector_cleanup.
It's pretty much the same for the encoder, btw.
I think the issue is more the two lines

	connector = &rgb->connector;
  	connector = drm_bridge_connector_init(rgb->drm_dev, encoder);

hence the connector = &rgb->connector being overwritten immediately after

Now that I look at it again, the whole approach looks strange.
drm_bridge_connector_init() creates the connector structure and
returns a pointer to it.
Totally agreed.

The main reason I was doing it that way, was the way it was done already 
in rockchip_lvds.c, where the connector was already existent in the 
struct rockchip_lvds (and was already used in the panel-case - all 
places where it is used accept pointers also, btw) and is *no* pointer - 
and is done already this very strange way.

I wanted to re-use it for the bridge-case and didn't want to differ in 
coding in rockchip-rgb to much.

The only reason I can think of, why it was done that way is, that we 
might need a pointer to a fully initialized struct drm_connector for 
some reason (drm_connector_cleanup ?), what we wouldn't have if have 
just a pointer and something goes wrong before drm_connector_init 
respectivly drm_bridge_connector_init.

Alex

So the first line below sets the connector pointer to point to the
&rgb->connector element and the second line then set a completely
different address into it.

So the connector element in rockchip_lvds and rockchip_rgb should actually
become a pointer itself to hold the connector element returned from
drm_bridge_connector_init() .


Heiko
quoted
Regards,

Alex
quoted
Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <redacted>
---
   drivers/gpu/drm/rockchip/rockchip_rgb.c | 1 -
   1 file changed, 1 deletion(-)
diff --git a/drivers/gpu/drm/rockchip/rockchip_rgb.c b/drivers/gpu/drm/rockchip/rockchip_rgb.c
index 09be9678f2bd..18fb84068a64 100644
--- a/drivers/gpu/drm/rockchip/rockchip_rgb.c
+++ b/drivers/gpu/drm/rockchip/rockchip_rgb.c
@@ -150,7 +150,6 @@ struct rockchip_rgb *rockchip_rgb_init(struct device *dev,
   	if (ret)
   		goto err_free_encoder;
   
-	connector = &rgb->connector;
   	connector = drm_bridge_connector_init(rgb->drm_dev, encoder);
   	if (IS_ERR(connector)) {
   		DRM_DEV_ERROR(drm_dev->dev,
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help