From eb8dd3abeb4dffab6c373e87d09fc3b5858ac158 Mon Sep 17 00:00:00 2001 From: Boris Brezillon Date: Fri, 9 Nov 2018 11:26:33 +0100 Subject: [PATCH] drm/vc4: Prefer PPF over TPZ when dst >= 2/3 src The HVS spec recommends using PPF when the downscaling ratio is between 2/3 and 1. Let's modify vc4_get_scaling_mode() to follow this recommendation. Signed-off-by: Boris Brezillon Reviewed-by: Eric Anholt Link: https://patchwork.freedesktop.org/patch/msgid/20181109102633.32603-2-boris.brezillon@bootlin.com --- drivers/gpu/drm/vc4/vc4_plane.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/vc4/vc4_plane.c b/drivers/gpu/drm/vc4/vc4_plane.c index 6caa678edcff..1728fb7d00ba 100644 --- a/drivers/gpu/drm/vc4/vc4_plane.c +++ b/drivers/gpu/drm/vc4/vc4_plane.c @@ -129,12 +129,12 @@ static const struct hvs_format *vc4_get_hvs_format(u32 drm_format) static enum vc4_scaling_mode vc4_get_scaling_mode(u32 src, u32 dst) { - if (dst > src) + if (dst == src) + return VC4_SCALING_NONE; + if (3 * dst >= 2 * src) return VC4_SCALING_PPF; - else if (dst < src) - return VC4_SCALING_TPZ; else - return VC4_SCALING_NONE; + return VC4_SCALING_TPZ; } static bool plane_enabled(struct drm_plane_state *state) -- 2.30.2