Hi all,

Am 22.09.21 um 19:31 schrieb Alex Bee:

Hi Heiko,

Am 22.09.21 um 18:45 schrieb Heiko Stübner:

quoted

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

quoted

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() .

It turns out, nothing bad happens (i.e. rockchip_rgb_fini, the only 
place where the connector is also used, isn't called if 
rockchip_rgb_init fails) - so it will be OK if we make the connector a 
pointer in struct rockchip_rgb. But we'll need to keep it a "full" 
struct drm_connector in struct rockchip_lvds, since in case it's a 
panel  it gets properties assigend before drm_connector_init is called 
and should for that reason initialized before.

I'll send a patch soon.

Alex

quoted

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,

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