Re: [PATCH v2] drm: rcar-du: turn rcar_du_group_get() into void and remove its return value check

Laurent Pinchart
2023-09-30T14:50:29Z

Hi Alexandra,

On Wed, Sep 27, 2023 at 01:44:38PM +0300, Alexandra Diupina wrote:
> rcar_du_group_get() never returns a negative
> error code (always returns 0), so change the comment
> about returned value, turn function into void (return
> code of rcar_du_group_get has been redundant for a
> long time, so perhaps it's just not required) and
> remove redundant error path handling in rcar_du_crtc_get()
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.

Using tools to find issues is fine in principle, but not even
compile-testing the resulting patch before submitting it is not.

> Fixes: 0bb63534fdf3 ("drm: rcar-du: Perform the initial CRTC setup from rcar_du_crtc_get()")
> Signed-off-by: Alexandra Diupina <adiupina@astralinux.ru>
> ---
> v2: rcar_du_group_get() is turned into void and its return
> value check is removed in rcar_du_crtc_get()
> drivers/gpu/drm/renesas/rcar-du/rcar_du_crtc.c | 6 +-----
> drivers/gpu/drm/renesas/rcar-du/rcar_du_group.c | 5 +----
> 2 files changed, 2 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/renesas/rcar-du/rcar_du_crtc.c b/drivers/gpu/drm/renesas/rcar-du/rcar_du_crtc.c
> index 7e175dbfd892..2be7c6e64d72 100644
> --- a/drivers/gpu/drm/renesas/rcar-du/rcar_du_crtc.c
> +++ b/drivers/gpu/drm/renesas/rcar-du/rcar_du_crtc.c
> @@ -565,17 +565,13 @@ static int rcar_du_crtc_get(struct rcar_du_crtc *rcrtc)
> if (ret < 0)
> goto error_clock;
>
> - ret = rcar_du_group_get(rcrtc->group);
> - if (ret < 0)
> - goto error_group;
> + rcar_du_group_get(rcrtc->group);
>
> rcar_du_crtc_setup(rcrtc);
> rcrtc->initialized = true;
>
> return 0;
>
> -error_group:
> - clk_disable_unprepare(rcrtc->extclock);
> error_clock:
> clk_disable_unprepare(rcrtc->clock);
> return ret;
> diff --git a/drivers/gpu/drm/renesas/rcar-du/rcar_du_group.c b/drivers/gpu/drm/renesas/rcar-du/rcar_du_group.c
> index 2ccd2581f544..7113025dabff 100644
> --- a/drivers/gpu/drm/renesas/rcar-du/rcar_du_group.c
> +++ b/drivers/gpu/drm/renesas/rcar-du/rcar_du_group.c
> @@ -199,10 +199,8 @@ static void rcar_du_group_setup(struct rcar_du_group *rgrp)
> * before accessing any hardware registers.
> *
> * This function must be called with the DRM mode_config lock held.
> - *
> - * Return 0 in case of success or a negative error code otherwise.
> */
> -int rcar_du_group_get(struct rcar_du_group *rgrp)
> +void rcar_du_group_get(struct rcar_du_group *rgrp)
> {
> if (rgrp->use_count)
> goto done;
> @@ -211,7 +209,6 @@ int rcar_du_group_get(struct rcar_du_group *rgrp)
>
> done:
> rgrp->use_count++;
> - return 0;
> }
>
> /*

--
Regards,

Laurent Pinchart