[PATCH 1/3] drm: Move drm_mode_setcrtc() local re-init to failure path

[Daniel Vetter]

On Tue, Nov 27, 2018 at 05:46:38PM -0500, Sean Paul wrote:
> From: Sean Paul <seanpaul at chromium.org>
> 
> Instead of always re-initializing the variables we need to clean up on
> out, move the re-initialization into the branch that goes back to retry
> label.
> 
> This is a lateral move right now, but will allow us to pull out the
> modeset locking into common code. I kept this change separate to make
> things easier to review.
> 
> Cc: Daniel Vetter <daniel at ffwll.ch>
> Signed-off-by: Sean Paul <seanpaul at chromium.org>

Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>

> ---
>  drivers/gpu/drm/drm_crtc.c | 16 +++++++++-------
>  1 file changed, 9 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> index 268a182ae1893..af4b94ce8e942 100644
> --- a/drivers/gpu/drm/drm_crtc.c
> +++ b/drivers/gpu/drm/drm_crtc.c
> @@ -570,9 +570,9 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data,
>  	struct drm_mode_crtc *crtc_req = data;
>  	struct drm_crtc *crtc;
>  	struct drm_plane *plane;
> -	struct drm_connector **connector_set, *connector;
> -	struct drm_framebuffer *fb;
> -	struct drm_display_mode *mode;
> +	struct drm_connector **connector_set = NULL, *connector;
> +	struct drm_framebuffer *fb = NULL;
> +	struct drm_display_mode *mode = NULL;
>  	struct drm_mode_set set;
>  	uint32_t __user *set_connectors_ptr;
>  	struct drm_modeset_acquire_ctx ctx;
> @@ -601,10 +601,6 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data,
>  	mutex_lock(&crtc->dev->mode_config.mutex);
>  	drm_modeset_acquire_init(&ctx, DRM_MODESET_ACQUIRE_INTERRUPTIBLE);
>  retry:
> -	connector_set = NULL;
> -	fb = NULL;
> -	mode = NULL;
> -
>  	ret = drm_modeset_lock_all_ctx(crtc->dev, &ctx);
>  	if (ret)
>  		goto out;
> @@ -766,6 +762,12 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data,
>  	}
>  	kfree(connector_set);
>  	drm_mode_destroy(dev, mode);
> +
> +	/* In case we need to retry... */
> +	connector_set = NULL;
> +	fb = NULL;
> +	mode = NULL;
> +
>  	if (ret == -EDEADLK) {
>  		ret = drm_modeset_backoff(&ctx);
>  		if (!ret)
> -- 
> Sean Paul, Software Engineer, Google / Chromium OS
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch