vc4/drm: Fix source offsets with DRM_FORMAT_P030

Spec says: bits [31:4] of the given address should point to
the 128-bit word containing the desired starting pixel,
and bits[3:0] should be between 0 and 11, indicating which
of the 12-pixels in that 128-bit word is the first pixel to be used

Signed-off-by: Dom Cobley <popcornmix@gmail.com>

diff --git a/drivers/gpu/drm/vc4/vc4_plane.c b/drivers/gpu/drm/vc4/vc4_plane.c
index 3d33fe3..4198eb8 100644 (file)
--- a/drivers/gpu/drm/vc4/vc4_plane.c
+++ b/drivers/gpu/drm/vc4/vc4_plane.c
@@ -824,9 +824,20 @@ static int vc4_plane_mode_set(struct drm_plane *plane,
                u32 tile_w, tile, x_off, pix_per_tile;
 
                if (fb->format->format == DRM_FORMAT_P030) {
+                       /*
+                        * Spec says: bits [31:4] of the given address should point to
+                        * the 128-bit word containing the desired starting pixel,
+                        * and bits[3:0] should be between 0 and 11, indicating which
+                        * of the 12-pixels in that 128-bit word is the first pixel to be used
+                        */
+                       u32 aligned = vc4_state->src_x / 12;
+                       u32 last_bits = vc4_state->src_x % 12;
+
+                       x_off = aligned * 16 + last_bits;
                        hvs_format = HVS_PIXEL_FORMAT_YCBCR_10BIT;
                        tiling = SCALER_CTL0_TILING_128B;
-                       tile_w = 96;
+                       tile_w = 128;
+                       pix_per_tile = 96;
                } else {
                        hvs_format = HVS_PIXEL_FORMAT_H264;
 
@@ -846,17 +857,16 @@ static int vc4_plane_mode_set(struct drm_plane *plane,
                        default:
                                break;
                        }
+                       pix_per_tile = tile_w / fb->format->cpp[0];
+                       x_off = (vc4_state->src_x % pix_per_tile) /
+                               (i ? h_subsample : 1) * fb->format->cpp[i];
                }
                if (param > SCALER_TILE_HEIGHT_MASK) {
                        DRM_DEBUG_KMS("SAND height too large (%d)\n",
                                      param);
                        return -EINVAL;
                }
-
-               pix_per_tile = tile_w / fb->format->cpp[0];
                tile = vc4_state->src_x / pix_per_tile;
-               x_off = vc4_state->src_x % pix_per_tile;
-
                /* Adjust the base pointer to the first pixel to be scanned
                 * out.
                 *
@@ -872,9 +882,7 @@ static int vc4_plane_mode_set(struct drm_plane *plane,
                        vc4_state->offsets[i] += src_y /
                                                 (i ? v_subsample : 1) *
                                                 tile_w;
-                       vc4_state->offsets[i] += x_off /
-                                                (i ? h_subsample : 1) *
-                                                fb->format->cpp[i];
+                       vc4_state->offsets[i] += x_off & ~(i ? 1 : 0);
                }
 
                pitch0 = VC4_SET_FIELD(param, SCALER_TILE_HEIGHT);