<html><body><p> <pre> Hi, Jason: On Sat, 2024-10-05 at 17:52 +0800, Jason-JH.Lin wrote: > If the constant alpha always set, the SoCs that is not supported the > ignore alpha bit will still use constant alpha. That will break the > original constant alpha setting of XRGB foramt for blend_modes > unsupported SoCs, such as MT8173. > > Make the constatnt alpha only set when setting has_alpha or supported > blend_modes SoC to fix the downgrade issue. I would like this patch to be cherry-picked to kernel 6.11 easily, so let this patch base on 6.12-rc1. > > Fixes: bc46eb5d5d77 ("drm/mediatek: Support DRM plane alpha in OVL") > Signed-off-by: Jason-JH.Lin <jason-jh.lin@mediatek.com> > --- > drivers/gpu/drm/mediatek/mtk_disp_ovl.c | 28 +++++++++++++++---------- > 1 file changed, 17 insertions(+), 11 deletions(-) > > diff --git a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c > index 703cd3f6c6d3..de3addd89442 100644 > --- a/drivers/gpu/drm/mediatek/mtk_disp_ovl.c > +++ b/drivers/gpu/drm/mediatek/mtk_disp_ovl.c > @@ -494,19 +494,25 @@ void mtk_ovl_layer_config(struct device *dev, unsigned int idx, > > con = mtk_ovl_fmt_convert(ovl, state); > if (state->base.fb) { > -con |= OVL_CON_AEN; > -con |= state->base.alpha & OVL_CON_ALPHA; > +/* > + * For blend_modes supported SoCs, always set constant alpha. > + * For blend_modes unsupported SoCs, set constant alpha when has_alpha is set. > + */ > +if (ovl->data->blend_modes || state->base.fb->format->has_alpha) { > +con |= OVL_CON_AEN; > +con |= state->base.alpha & OVL_CON_ALPHA; MT8173 does not support ignore pixel alpha, so OVL_CON_AEN would be disabled for XRGB. And this is not related to plane alpha, so plane alpha setting should be moved out of here. > +} > + > +/* > + * Although the alpha channel can be ignored, CONST_BLD must be enabled > + * for XRGB format, otherwise OVL will still read the value from memory. > + * For RGB888 related formats, whether CONST_BLD is enabled or not won't > + * affect the result. Therefore we use !has_alpha as the condition. > + */ > +if (blend_mode == DRM_MODE_BLEND_PIXEL_NONE || !state->base.fb->format->has_alpha) > +ignore_pixel_alpha = OVL_CONST_BLEND; This modification is not related to the bug fix, so separate to another patch. Regards, CK > } > > -/* CONST_BLD must be enabled for XRGB formats although the alpha channel > - * can be ignored, or OVL will still read the value from memory. > - * For RGB888 related formats, whether CONST_BLD is enabled or not won't > - * affect the result. Therefore we use !has_alpha as the condition. > - */ > -if ((state->base.fb && !state->base.fb->format->has_alpha) || > - blend_mode == DRM_MODE_BLEND_PIXEL_NONE) > -ignore_pixel_alpha = OVL_CONST_BLEND; > - > if (pending->rotation & DRM_MODE_REFLECT_Y) { > con |= OVL_CON_VIRT_FLIP; > addr += (pending->height - 1) * pending->pitch; </pre> </p></body></html><pre>************* MEDIATEK Confidentiality Notice ******************** The information contained in this e-mail message (including any attachments) may be confidential, proprietary, privileged, or otherwise exempt from disclosure under applicable laws. It is intended to be conveyed only to the designated recipient(s). Any use, dissemination, distribution, printing, retaining or copying of this e-mail (including its attachments) by unintended recipient(s) is strictly prohibited and may be unlawful. If you are not an intended recipient of this e-mail, or believe that you have received this e-mail in error, please notify the sender immediately (by replying to this e-mail), delete any and all copies of this e-mail (including any attachments) from your system, and do not disclose the content of this e-mail to any other person. Thank you! </pre>