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() . Heikoquoted
Regards, Alexquoted
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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