Re: [PATCH v4 3/4] drm/mediatek: Add gamma correction.

From: Philipp Zabel
Date: Thu Aug 11 2016 - 03:51:59 EST


Am Donnerstag, den 28.07.2016, 10:22 +0800 schrieb Bibby Hsieh:
> Add gamma set function to correct brightness values.
> It applies arbitrary mapping curve to compensate the
> incorrect transfer function of the panel.
>
> Signed-off-by: Bibby Hsieh <bibby.hsieh@xxxxxxxxxxxx>
> ---
> drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 8 ++++++-
> drivers/gpu/drm/mediatek/mtk_drm_crtc.h | 1 +
> drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.c | 31 +++++++++++++++++++++++++++
> drivers/gpu/drm/mediatek/mtk_drm_ddp_comp.h | 10 +++++++++
> 4 files changed, 49 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> index 24aa3ba..cbb460a5 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> @@ -409,6 +409,9 @@ static void mtk_drm_crtc_atomic_flush(struct drm_crtc *crtc,
> }
> if (pending_planes)
> mtk_crtc->pending_planes = true;
> + if (crtc->state->color_mgmt_changed)
> + for (i = 0; i < mtk_crtc->ddp_comp_nr; i++)
> + mtk_ddp_gamma_set(mtk_crtc->ddp_comp[i], crtc->state);
> }
>
> static const struct drm_crtc_funcs mtk_crtc_funcs = {
> @@ -418,6 +421,7 @@ static const struct drm_crtc_funcs mtk_crtc_funcs = {
> .reset = mtk_drm_crtc_reset,
> .atomic_duplicate_state = mtk_drm_crtc_duplicate_state,
> .atomic_destroy_state = mtk_drm_crtc_destroy_state,
> + .gamma_set = drm_atomic_helper_legacy_gamma_set,
> };
>
> static const struct drm_crtc_helper_funcs mtk_crtc_helper_funcs = {
> @@ -568,7 +572,9 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
> &mtk_crtc->planes[1].base, pipe);
> if (ret < 0)
> goto unprepare;
> -
> + drm_mode_crtc_set_gamma_size(&mtk_crtc->base, MTK_LUT_SIZE);
> + drm_helper_crtc_enable_color_mgmt(&mtk_crtc->base, MTK_LUT_SIZE,
> + MTK_LUT_SIZE);

I have applied all four patches and rebased onto v4.8-rc1, replacing
drm_helper_crtc_enable_color_mgmt with:

drm_crtc_enable_color_mgmt(&mtk_crtc->base, MTK_LUT_SIZE,
true, MTK_LUT_SIZE);

(See https://patchwork.kernel.org/patch/9160987/)

regards
Philipp