[PATCH 02/13] drm/sun4i: vi scaler: Fix coefficient selection

[Jernej Skrabec <jernej.skrabec@gmail.com>]

Currently, vertical coefficients are selected based on horizontal
scaling, which is wrong. Additionally, chroma coefficients should be
selected based on format subsampling.

Fix all that.

Fixes: b862a648de3b ("drm/sun4i: Add support for HW scaling to DE2")
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
---
 drivers/gpu/drm/sun4i/sun8i_vi_scaler.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun8i_vi_scaler.c b/drivers/gpu/drm/sun4i/sun8i_vi_scaler.c
index 3dec4eeb1ba2..d4412a62c2f0 100644
--- a/drivers/gpu/drm/sun4i/sun8i_vi_scaler.c
+++ b/drivers/gpu/drm/sun4i/sun8i_vi_scaler.c
@@ -894,20 +894,26 @@ static void sun8i_vi_scaler_set_coeff(struct regmap *map, u32 base,
 			     lan3coefftab32_left[offset + i]);
 		regmap_write(map, SUN8I_SCALER_VSU_YHCOEFF1(base, i),
 			     lan3coefftab32_right[offset + i]);
+	}
+	offset = sun8i_vi_scaler_coef_index(vstep) *
+			SUN8I_VI_SCALER_COEFF_COUNT;
+	for (i = 0; i < SUN8I_VI_SCALER_COEFF_COUNT; i++)
+		regmap_write(map, SUN8I_SCALER_VSU_YVCOEFF(base, i),
+			     lan2coefftab32[offset + i]);
+
+	offset = sun8i_vi_scaler_coef_index(hstep / format->hsub) *
+			SUN8I_VI_SCALER_COEFF_COUNT;
+	for (i = 0; i < SUN8I_VI_SCALER_COEFF_COUNT; i++) {
 		regmap_write(map, SUN8I_SCALER_VSU_CHCOEFF0(base, i),
 			     ch_left[offset + i]);
 		regmap_write(map, SUN8I_SCALER_VSU_CHCOEFF1(base, i),
 			     ch_right[offset + i]);
 	}
-
-	offset = sun8i_vi_scaler_coef_index(hstep) *
+	offset = sun8i_vi_scaler_coef_index(vstep / format->vsub) *
 			SUN8I_VI_SCALER_COEFF_COUNT;
-	for (i = 0; i < SUN8I_VI_SCALER_COEFF_COUNT; i++) {
-		regmap_write(map, SUN8I_SCALER_VSU_YVCOEFF(base, i),
-			     lan2coefftab32[offset + i]);
+	for (i = 0; i < SUN8I_VI_SCALER_COEFF_COUNT; i++)
 		regmap_write(map, SUN8I_SCALER_VSU_CVCOEFF(base, i),
 			     cy[offset + i]);
-	}
 }
 
 void sun8i_vi_scaler_enable(struct sun8i_layer *layer, bool enable)
-- 
2.43.0