| Message ID | 20241009034646.13143-2-jason-jh.lin@mediatek.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Fix degradation problem of alpha blending series | expand |
Il 09/10/24 05:46, Jason-JH.Lin ha scritto: > OVL_CON_AEN is for alpha blending enable. > For the SoC that is supported the blend_modes, OVL_CON_AEN will always > enabled to use constant alpha and then use the ignore_pixel_alpha bit > to do the alpha blending for XRGB8888 format. > Note that ignore pixel alpha bit is not supported if the SoC is not > supported the blend_modes. > So it will break the original setting of XRGB8888 format for the > blend_modes unsupported SoCs, such as MT8173. > > To fix the downgrade issue, enable alpha blending only when a valid > blend_mode or has_alpha is set. > > Fixes: bc46eb5d5d77 ("drm/mediatek: Support DRM plane alpha in OVL") > Signed-off-by: Jason-JH.Lin <jason-jh.lin@mediatek.com> > Reviewed-by: CK Hu <ck.hu@mediatek.com> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
diff --git a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c index 89b439dcf3a6..047cd1796a51 100644 --- a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c +++ b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c @@ -473,8 +473,14 @@ void mtk_ovl_layer_config(struct device *dev, unsigned int idx, con = ovl_fmt_convert(ovl, fmt, blend_mode); if (state->base.fb) { - con |= OVL_CON_AEN; con |= state->base.alpha & OVL_CON_ALPHA; + + /* + * For blend_modes supported SoCs, always enable alpha blending. + * For blend_modes unsupported SoCs, enable alpha blending when has_alpha is set. + */ + if (blend_mode || state->base.fb->format->has_alpha) + con |= OVL_CON_AEN; } /* CONST_BLD must be enabled for XRGB formats although the alpha channel
OVL_CON_AEN is for alpha blending enable. For the SoC that is supported the blend_modes, OVL_CON_AEN will always enabled to use constant alpha and then use the ignore_pixel_alpha bit to do the alpha blending for XRGB8888 format. Note that ignore pixel alpha bit is not supported if the SoC is not supported the blend_modes. So it will break the original setting of XRGB8888 format for the blend_modes unsupported SoCs, such as MT8173. To fix the downgrade issue, enable alpha blending only when a valid blend_mode or has_alpha is set. Fixes: bc46eb5d5d77 ("drm/mediatek: Support DRM plane alpha in OVL") Signed-off-by: Jason-JH.Lin <jason-jh.lin@mediatek.com> Reviewed-by: CK Hu <ck.hu@mediatek.com> --- drivers/gpu/drm/mediatek/mtk_disp_ovl.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)