[PATCH v2 6/6] drm/i915: Do not do fb src adjustments for NV12

[Vidya Srinivas]

We skip src trunction/adjustments for
NV12 case and handle the sizes directly.
Without this, pipe fifo underruns are seen on APL/KBL.

v2: For NV12, making the src coordinates multiplier of 4

Credits-to: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Signed-off-by: Vidya Srinivas <vidya.srinivas at intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 11 +++++++++++
 drivers/gpu/drm/i915/intel_sprite.c  | 15 +++++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index bc83f10..f64708f 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -12978,6 +12978,10 @@ intel_check_primary_plane(struct intel_plane *plane,
 	bool can_position = false;
 	int ret;
 	uint32_t pixel_format = 0;
+	struct drm_plane_state *plane_state = &state->base;
+	struct drm_rect *src = &plane_state->src;
+
+	*src = drm_plane_state_src(plane_state);
 
 	if (INTEL_GEN(dev_priv) >= 9) {
 		/* use scaler when colorkey is not required */
@@ -13001,6 +13005,13 @@ intel_check_primary_plane(struct intel_plane *plane,
 	if (!state->base.fb)
 		return 0;
 
+	if (pixel_format == DRM_FORMAT_NV12) {
+		src->x1 = (((src->x1 >> 16)/4)*4) << 16;
+		src->x2 = (((src->x2 >> 16)/4)*4) << 16;
+		src->y1 = (((src->y1 >> 16)/4)*4) << 16;
+		src->y2 = (((src->y2 >> 16)/4)*4) << 16;
+	}
+
 	if (INTEL_GEN(dev_priv) >= 9) {
 		ret = skl_check_plane_surface(crtc_state, state);
 		if (ret)
diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
index 8b7947d..c1dd85e 100644
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/drivers/gpu/drm/i915/intel_sprite.c
@@ -1035,11 +1035,20 @@ intel_check_sprite_plane(struct intel_plane *plane,
 			return vscale;
 		}
 
+		if (fb->format->format == DRM_FORMAT_NV12) {
+			if (src->x2 >> 16 == 16)
+				src->x2 = 16 << 16;
+			if (src->y2 >> 16 == 16)
+				src->y2 = 16 << 16;
+			goto nv12_min_no_clip;
+		}
+
 		/* Make the source viewport size an exact multiple of the scaling factors. */
 		drm_rect_adjust_size(src,
 				     drm_rect_width(dst) * hscale - drm_rect_width(src),
 				     drm_rect_height(dst) * vscale - drm_rect_height(src));
 
+nv12_min_no_clip:
 		drm_rect_rotate_inv(src, fb->width << 16, fb->height << 16,
 				    state->base.rotation);
 
@@ -1105,6 +1114,12 @@ intel_check_sprite_plane(struct intel_plane *plane,
 		src->x2 = (src_x + src_w) << 16;
 		src->y1 = src_y << 16;
 		src->y2 = (src_y + src_h) << 16;
+		if (fb->format->format == DRM_FORMAT_NV12) {
+			src->x1 = (((src->x1 >> 16)/4)*4) << 16;
+			src->x2 = (((src->x2 >> 16)/4)*4) << 16;
+			src->y1 = (((src->y1 >> 16)/4)*4) << 16;
+			src->y2 = (((src->y2 >> 16)/4)*4) << 16;
+		}
 	}
 
 	dst->x1 = crtc_x;
-- 
2.7.4