Re: [linux-sunxi] [PATCH 11/17] drm/sun4i: Wire in DE2 scaler support

[Julian Calaby]

Hi Jernej,

On Tue, Nov 28, 2017 at 7:57 AM, Jernej Skrabec <jernej.skrabec@xxxxxxxx> wrote:
> Calculate scaling parameters and call appropriate scaler set up
> function.
>
> Signed-off-by: Jernej Skrabec <jernej.skrabec@xxxxxxxx>
> ---
>  drivers/gpu/drm/sun4i/sun8i_layer.c |  12 +++-
>  drivers/gpu/drm/sun4i/sun8i_mixer.c | 115 +++++++++++++++++++++++++-----------
>  drivers/gpu/drm/sun4i/sun8i_mixer.h |   4 --
>  3 files changed, 90 insertions(+), 41 deletions(-)
>
> diff --git a/drivers/gpu/drm/sun4i/sun8i_layer.c b/drivers/gpu/drm/sun4i/sun8i_layer.c
> index e1b6ad82145e..6860271e5415 100644
> --- a/drivers/gpu/drm/sun4i/sun8i_layer.c
> +++ b/drivers/gpu/drm/sun4i/sun8i_layer.c
> @@ -41,9 +44,14 @@ static int sun8i_mixer_layer_atomic_check(struct drm_plane *plane,
>         clip.x2 = crtc_state->adjusted_mode.hdisplay;
>         clip.y2 = crtc_state->adjusted_mode.vdisplay;
>
> +       scaler_supported = !!(layer->mixer->cfg->scaler_mask & BIT(layer->id));
> +
> +       min_scale = scaler_supported ? 1 : DRM_PLANE_HELPER_NO_SCALING;
> +       max_scale = scaler_supported ? (1UL << 20) - 1 :
> +                                      DRM_PLANE_HELPER_NO_SCALING;
> +

Disclaimer: I hate ternaries, but this looks like it'd be better
written as an if statement. I.e.

min_scale = DRM_PLANE_HELPER_NO_SCALING;
max_scale = DRM_PLANE_HELPER_NO_SCALING;

if (layer->mixer->cfg->scaler_mask & BIT(layer->id)) {
    min_scale = 1;
    max_scale = (1UL << 20) - 1;
}

However the compiler will probably sort it all out anyway, so it
probably doesn't matter that much, except for style.

Thanks,

-- 
Julian Calaby

Email: julian.calaby@xxxxxxxxx
Profile: http://www.google.com/profiles/julian.calaby/