[PATCH v4 05/13] drm/msm/dpu: move scaling limitations out of the hw_catalog

[Abhinav Kumar]

On 3/13/2024 5:02 PM, Dmitry Baryshkov wrote:
> Max upscale / downscale factors are constant between platforms. In
> preparation to adding support for virtual planes and allocating SSPP
> blocks on demand move max scaling factors out of the HW catalog and
> handle them in the dpu_plane directly. If any of the scaling blocks gets
> different limitations, this will have to be handled separately, after
> the plane refactoring.
> 
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
> ---
>   drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.c | 12 ------------
>   drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h |  4 ----
>   drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c      | 16 +++++++++++++---
>   3 files changed, 13 insertions(+), 19 deletions(-)
> 

<Snip>

> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
> index 70d6a8989e1a..6360052523b5 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c
> @@ -785,12 +785,15 @@ static int dpu_plane_atomic_check_pipe(struct dpu_plane *pdpu,
>   	return 0;
>   }
>   
> +#define MAX_UPSCALE_RATIO	20
> +#define MAX_DOWNSCALE_RATIO	4
> +
>   static int dpu_plane_atomic_check(struct drm_plane *plane,
>   				  struct drm_atomic_state *state)
>   {
>   	struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(state,
>   										 plane);
> -	int ret = 0, min_scale;
> +	int ret = 0, min_scale, max_scale;
>   	struct dpu_plane *pdpu = to_dpu_plane(plane);
>   	struct dpu_kms *kms = _dpu_plane_get_kms(&pdpu->base);
>   	u64 max_mdp_clk_rate = kms->perf.max_core_clk_rate;
> @@ -822,10 +825,17 @@ static int dpu_plane_atomic_check(struct drm_plane *plane,
>   	pipe_hw_caps = pipe->sspp->cap;
>   	sblk = pipe->sspp->cap->sblk;
>   
> -	min_scale = FRAC_16_16(1, sblk->maxupscale);
> +	if (sblk->scaler_blk.len) {
> +		min_scale = FRAC_16_16(1, MAX_UPSCALE_RATIO);
> +		max_scale = MAX_DOWNSCALE_RATIO << 16;
> +	} else {
> +		min_scale = 1 << 16;
> +		max_scale = 1 << 16;

You can use DRM_PLANE_NO_SCALING instead.

> +	}
> +
>   	ret = drm_atomic_helper_check_plane_state(new_plane_state, crtc_state,
>   						  min_scale,
> -						  sblk->maxdwnscale << 16,
> +						  max_scale,
>   						  true, true);

I am missing something here.

As per the documentation of this API, min and max are the scaling limits 
of both directions and not max_upscale and max_downscale.

**
837  * drm_atomic_helper_check_plane_state() - Check plane state for 
validity
838  * @plane_state: plane state to check
839  * @crtc_state: CRTC state to check
840  * @min_scale: minimum @src:@dest scaling factor in 16.16 fixed point
841  * @max_scale: maximum @src:@dest scaling factor in 16.16 fixed point
842  * @can_position: is it legal to position the plane such that it


But this change is passing max_upscale and max_downscale as the min and 
max resp. Isnt that wrong?


>   	if (ret) {
>   		DPU_DEBUG_PLANE(pdpu, "Check plane state failed (%d)\n", ret);