linux-kernel - Re: [PATCH] drm/kms/atomic: Used existing func for checking fb geometry

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Date:   Fri, 27 Jul 2018 11:51:27 +0200
From:   Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>
To:     Satendra Singh Thakur <satendra.t@...sung.com>,
        Gustavo Padovan <gustavo@...ovan.org>,
        Sean Paul <seanpaul@...omium.org>,
        David Airlie <airlied@...ux.ie>,
        dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Cc:     vineet.j@...sung.com, hemanshu.s@...sung.com, sst2005@...il.com
Subject: Re: [PATCH] drm/kms/atomic: Used existing func for checking fb
 geometry

Op 27-07-18 om 10:38 schreef Satendra Singh Thakur:
> 1.In the func drm_atomic_plane_check, the fb geometry checking code
> can be replaced by func drm_framebuffer_check_src_coords, this will
> remove several redundant lines of code.
> 2. Currently, in the func drm_atomic_plane_check;
> there are 3 if statements in the beginning with total 5 conditions.
> these conditions are
> crtc is NULL but fb is non-NULL
> if (state->crtc && !state->fb)
> crtc is non-NULL but fb is NULL
> if (state->fb && !state->crtc)
> crtc is NULL (and fb is also NULL)
> if (!state->crtc)
>
> The same code can be re-written using 2 if statements and 4 conditions.
> first we check whether crtc and fb both are NULL
> if (!state->crtc && !state->fb)
> then we check either crtc or fb is NULL
> if (!state->crtc || !state->fb)
>
> Signed-off-by: Satendra Singh Thakur <satendra.t@...sung.com>
> ---
>  drivers/gpu/drm/drm_atomic.c | 37 +++++++++----------------------------
>  1 file changed, 9 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
> index 895741e..1cddab8 100644
> --- a/drivers/gpu/drm/drm_atomic.c
> +++ b/drivers/gpu/drm/drm_atomic.c
> @@ -909,22 +909,16 @@ plane_switching_crtc(struct drm_atomic_state *state,
>  static int drm_atomic_plane_check(struct drm_plane *plane,
>  		struct drm_plane_state *state)
>  {
> -	unsigned int fb_width, fb_height;
>  	int ret;
>  
> -	/* either *both* CRTC and FB must be set, or neither */
> -	if (state->crtc && !state->fb) {
> -		DRM_DEBUG_ATOMIC("CRTC set but no FB\n");
> -		return -EINVAL;
> -	} else if (state->fb && !state->crtc) {
> -		DRM_DEBUG_ATOMIC("FB set but no CRTC\n");
> -		return -EINVAL;
> -	}
> -
>  	/* if disabled, we don't care about the rest of the state: */
> -	if (!state->crtc)
> +	if (!state->crtc && !state->fb)
>  		return 0;
> -
> +	/* both CRTC and FB must be set*/
> +	if (!state->crtc || !state->fb) {
> +		DRM_DEBUG_ATOMIC("Either no CRTC or no FB\n");
> +		return -EINVAL;
> +	}
>  	/* Check whether this plane is usable on this CRTC */
>  	if (!(plane->possible_crtcs & drm_crtc_mask(state->crtc))) {
>  		DRM_DEBUG_ATOMIC("Invalid crtc for plane\n");
This should be a separate patch?
> @@ -954,24 +948,11 @@ static int drm_atomic_plane_check(struct drm_plane *plane,
>  		return -ERANGE;
>  	}
>  
> -	fb_width = state->fb->width << 16;
> -	fb_height = state->fb->height << 16;
> -
>  	/* Make sure source coordinates are inside the fb. */
> -	if (state->src_w > fb_width ||
> -	    state->src_x > fb_width - state->src_w ||
> -	    state->src_h > fb_height ||
> -	    state->src_y > fb_height - state->src_h) {
> -		DRM_DEBUG_ATOMIC("Invalid source coordinates "
> -				 "%u.%06ux%u.%06u+%u.%06u+%u.%06u (fb %ux%u)\n",
> -				 state->src_w >> 16, ((state->src_w & 0xffff) * 15625) >> 10,
> -				 state->src_h >> 16, ((state->src_h & 0xffff) * 15625) >> 10,
> -				 state->src_x >> 16, ((state->src_x & 0xffff) * 15625) >> 10,
> -				 state->src_y >> 16, ((state->src_y & 0xffff) * 15625) >> 10,
> -				 state->fb->width, state->fb->height);
> +	ret = drm_framebuffer_check_src_coords(state->src_x, state->src_y,
> +		state->src_w, state->src_h, state->fb);
> +	if (ret)
>  		return -ENOSPC;
Change this to return ret, no need to swallow errors. :)
> -	}
> -
>  	if (plane_switching_crtc(state->state, plane, state)) {
>  		DRM_DEBUG_ATOMIC("[PLANE:%d:%s] switching CRTC directly\n",
>  				 plane->base.id, plane->name);