openwrt/target/linux/brcm2708/patches-4.14/950-0131-drm-vc4-Fix-pitch-setup-for-T-format-scanout.patch

From 82f8b13481afeb2400bce276cf88a757fac87a21 Mon Sep 17 00:00:00 2001
From: Eric Anholt <eric@anholt.net>
Date: Fri, 14 Jul 2017 17:33:08 -0700
Subject: [PATCH 131/454] drm/vc4: Fix pitch setup for T-format scanout.

The documentation said to use src_w here, and I didn't consider that
we actually needed to be using pitch somewhere in our setup.  Fixes
scanout on my DSI panel when X11 does initial setup with 1920x1080
HDMI and 800x480 DSI both at 0,0 of the same framebuffer.

Signed-off-by: Eric Anholt <eric@anholt.net>
Fixes: 98830d91da08 ("drm/vc4: Add T-format scanout support.")
---
 drivers/gpu/drm/vc4/vc4_plane.c | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

--- a/drivers/gpu/drm/vc4/vc4_plane.c
+++ b/drivers/gpu/drm/vc4/vc4_plane.c
@@ -549,14 +549,24 @@ static int vc4_plane_mode_set(struct drm
 		tiling = SCALER_CTL0_TILING_LINEAR;
 		pitch0 = VC4_SET_FIELD(fb->pitches[0], SCALER_SRC_PITCH);
 		break;
-	case DRM_FORMAT_MOD_BROADCOM_VC4_T_TILED:
+
+	case DRM_FORMAT_MOD_BROADCOM_VC4_T_TILED: {
+		/* For T-tiled, the FB pitch is "how many bytes from
+		 * one row to the next, such that pitch * tile_h ==
+		 * tile_size * tiles_per_row."
+		 */
+		u32 tile_size_shift = 12;
+		u32 tile_h_shift = 5;
+		u32 tiles_w = fb->pitches[0] >> (tile_size_shift - tile_h_shift);
+
 		tiling = SCALER_CTL0_TILING_256B_OR_T;
 
-		pitch0 = (VC4_SET_FIELD(0, SCALER_PITCH0_TILE_Y_OFFSET),
-			  VC4_SET_FIELD(0, SCALER_PITCH0_TILE_WIDTH_L),
-			  VC4_SET_FIELD((vc4_state->src_w[0] + 31) >> 5,
-					SCALER_PITCH0_TILE_WIDTH_R));
+		pitch0 = (VC4_SET_FIELD(0, SCALER_PITCH0_TILE_Y_OFFSET) |
+			  VC4_SET_FIELD(0, SCALER_PITCH0_TILE_WIDTH_L) |
+			  VC4_SET_FIELD(tiles_w, SCALER_PITCH0_TILE_WIDTH_R));
 		break;
+	}
+
 	default:
 		DRM_DEBUG_KMS("Unsupported FB tiling flag 0x%16llx",
 			      (long long)fb->modifier);