From: Lyude Paul <lyude@xxxxxxxxxx> [ Upstream commit fb2420b701edbf96c2b6d557f0139902f455dc2b ] While we expose the ability to turn off hardware dithering for nouveau, we actually make the mistake of turning it on anyway, due to dithering_depth containing a non-zero value if our dithering depth isn't also set to 6 bpc. So, fix it by never enabling dithering when it's disabled. Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx> Reviewed-by: Ben Skeggs <bskeggs@xxxxxxxxxx> Acked-by: Dave Airlie <airlied@xxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20200627194657.156514-6-lyude@xxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/gpu/drm/nouveau/dispnv50/head.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-) diff --git a/drivers/gpu/drm/nouveau/dispnv50/head.c b/drivers/gpu/drm/nouveau/dispnv50/head.c index 8f6455697ba72..ed6819519f6d8 100644 --- a/drivers/gpu/drm/nouveau/dispnv50/head.c +++ b/drivers/gpu/drm/nouveau/dispnv50/head.c @@ -84,18 +84,20 @@ nv50_head_atomic_check_dither(struct nv50_head_atom *armh, { u32 mode = 0x00; - if (asyc->dither.mode == DITHERING_MODE_AUTO) { - if (asyh->base.depth > asyh->or.bpc * 3) - mode = DITHERING_MODE_DYNAMIC2X2; - } else { - mode = asyc->dither.mode; - } + if (asyc->dither.mode) { + if (asyc->dither.mode == DITHERING_MODE_AUTO) { + if (asyh->base.depth > asyh->or.bpc * 3) + mode = DITHERING_MODE_DYNAMIC2X2; + } else { + mode = asyc->dither.mode; + } - if (asyc->dither.depth == DITHERING_DEPTH_AUTO) { - if (asyh->or.bpc >= 8) - mode |= DITHERING_DEPTH_8BPC; - } else { - mode |= asyc->dither.depth; + if (asyc->dither.depth == DITHERING_DEPTH_AUTO) { + if (asyh->or.bpc >= 8) + mode |= DITHERING_DEPTH_8BPC; + } else { + mode |= asyc->dither.depth; + } } asyh->dither.enable = mode; -- 2.25.1
