drm/i915: Upscale scaler max scale for NV12

This patch updates scaler max limit support for NV12

v2: Rebased (me)

v3: Rebased (me)

v4: Missed the Tested-by/Reviewed-by in the previous series
Adding the same to commit message in this version.

v5: Addressed review comments from Ville and rebased
- calculation of max_scale to be made
less convoluted by splitting it up a bit
- Indentation errors to be fixed in the series

v6: Rebased (me)
Fixed review comments from Paauwe, Bob J
Previous version, where a split of calculation
was done, was wrong. Fixed that issue here.

v7: Rebased (me)

v8: Rebased (me)

v9: Rebased (me)

v10: Rebased (me)

v11: Addressed review comments from Shashank Sharma
Alignment issues fixed.
When call to skl_update_scaler is made, 0 was being
sent instead of pixel_format.
When crtc update scaler is called, we dont have the
fb to derive the pixel format. Added the function
parameter bool plane_scaler_check to account for this.

v12: Fixed failure in IGT debugfs_test.
fb is NULL in skl_update_scaler_plane
Due to this, accessing fb->format caused failure.
Patch checks fb before using.

v13: In the previous version there was a flaw.
In skl_update_scaler during plane_scaler_check
if the format was non-NV12, it would set need_scaling
to false. This could reset the previously set need_scaling
from a previous condition check. Patch fixes this.
Patch also adds minimum src height for YUV 420 formats
to 16 (as defined in BSpec) and adds for checking this
range.

v14: Addressed review comments from Maarten
Just add a check for NV12 min src height in
skl_update_scaler and retain the remaining checks
as is. Added Reviewed By from Juha-Pekka Heikkila.

v15: Rebased the series.

v16: Changed fb height restriction to be >= 16 as per
Bspec. Earlier it was > 16.

v17: Adding src width and height to be mult of 4 restriction
to avoid pipe fifo underruns for NV12.

Credits-to: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Tested-by: Clinton Taylor <clinton.a.taylor@intel.com>
Reviewed-by: Clinton Taylor <clinton.a.taylor@intel.com>
Reviewed-by: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>
Signed-off-by: Chandra Konduru <chandra.konduru@intel.com>
Signed-off-by: Nabendu Maiti <nabendu.bikash.maiti@intel.com>
Signed-off-by: Vidya Srinivas <vidya.srinivas@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1523245273-30264-15-git-send-email-vidya.srinivas@intel.com

drivers/gpu/drm/i915/intel_display.c

@@ -3483,6 +3483,8 @@ static u32 skl_plane_ctl_format(uint32_t pixel_format)
 		return PLANE_CTL_FORMAT_YUV422 | PLANE_CTL_YUV422_UYVY;
 	case DRM_FORMAT_VYUY:
 		return PLANE_CTL_FORMAT_YUV422 | PLANE_CTL_YUV422_VYUY;
+	case DRM_FORMAT_NV12:
+		return PLANE_CTL_FORMAT_NV12;
 	default:
 		MISSING_CASE(pixel_format);
 	}
@@ -4724,7 +4726,9 @@ static void cpt_verify_modeset(struct drm_device *dev, int pipe)
 static int
 skl_update_scaler(struct intel_crtc_state *crtc_state, bool force_detach,
 		  unsigned int scaler_user, int *scaler_id,
-		  int src_w, int src_h, int dst_w, int dst_h)
+		  int src_w, int src_h, int dst_w, int dst_h,
+		  bool plane_scaler_check,
+		  uint32_t pixel_format)
 {
 	struct intel_crtc_scaler_state *scaler_state =
 		&crtc_state->scaler_state;
@@ -4742,6 +4746,10 @@ skl_update_scaler(struct intel_crtc_state *crtc_state, bool force_detach,
 	 */
 	need_scaling = src_w != dst_w || src_h != dst_h;
 
+	if (plane_scaler_check)
+		if (pixel_format == DRM_FORMAT_NV12)
+			need_scaling = true;
+
 	if (crtc_state->ycbcr420 && scaler_user == SKL_CRTC_INDEX)
 		need_scaling = true;
 
@@ -4781,6 +4789,13 @@ skl_update_scaler(struct intel_crtc_state *crtc_state, bool force_detach,
 		return 0;
 	}
 
+	if (plane_scaler_check && pixel_format == DRM_FORMAT_NV12 &&
+	    (src_h < SKL_MIN_YUV_420_SRC_H || (src_w % 4) != 0 ||
+	     (src_h % 4) != 0)) {
+		DRM_DEBUG_KMS("NV12: src dimensions not met\n");
+		return -EINVAL;
+	}
+
 	/* range checks */
 	if (src_w < SKL_MIN_SRC_W || src_h < SKL_MIN_SRC_H ||
 	    dst_w < SKL_MIN_DST_W || dst_h < SKL_MIN_DST_H ||
@@ -4822,7 +4837,8 @@ int skl_update_scaler_crtc(struct intel_crtc_state *state)
 	return skl_update_scaler(state, !state->base.active, SKL_CRTC_INDEX,
 				 &state->scaler_state.scaler_id,
 				 state->pipe_src_w, state->pipe_src_h,
-		adjusted_mode->crtc_hdisplay, adjusted_mode->crtc_vdisplay);
+				 adjusted_mode->crtc_hdisplay,
+				 adjusted_mode->crtc_vdisplay, false, 0);
 }
 
 /**
@@ -4851,7 +4867,8 @@ static int skl_update_scaler_plane(struct intel_crtc_state *crtc_state,
 				drm_rect_width(&plane_state->base.src) >> 16,
 				drm_rect_height(&plane_state->base.src) >> 16,
 				drm_rect_width(&plane_state->base.dst),
-				drm_rect_height(&plane_state->base.dst));
+				drm_rect_height(&plane_state->base.dst),
+				fb ? true : false, fb ? fb->format->format : 0);
 
 	if (ret || plane_state->scaler_id < 0)
 		return ret;
@@ -4877,6 +4894,7 @@ static int skl_update_scaler_plane(struct intel_crtc_state *crtc_state,
 	case DRM_FORMAT_YVYU:
 	case DRM_FORMAT_UYVY:
 	case DRM_FORMAT_VYUY:
+	case DRM_FORMAT_NV12:
 		break;
 	default:
 		DRM_DEBUG_KMS("[PLANE:%d:%s] FB:%d unsupported scaling format 0x%x\n",
@@ -12877,11 +12895,13 @@ intel_cleanup_plane_fb(struct drm_plane *plane,
 }
 
 int
-skl_max_scale(struct intel_crtc *intel_crtc, struct intel_crtc_state *crtc_state)
+skl_max_scale(struct intel_crtc *intel_crtc,
+	      struct intel_crtc_state *crtc_state,
+	      uint32_t pixel_format)
 {
 	struct drm_i915_private *dev_priv;
-	int max_scale;
-	int crtc_clock, max_dotclk;
+	int max_scale, mult;
+	int crtc_clock, max_dotclk, tmpclk1, tmpclk2;
 
 	if (!intel_crtc || !crtc_state->base.enable)
 		return DRM_PLANE_HELPER_NO_SCALING;
@@ -12903,8 +12923,10 @@ skl_max_scale(struct intel_crtc *intel_crtc, struct intel_crtc_state *crtc_state
 	 *            or
 	 *    cdclk/crtc_clock
 	 */
-	max_scale = min((1 << 16) * 3 - 1,
-			(1 << 8) * ((max_dotclk << 8) / crtc_clock));
+	mult = pixel_format == DRM_FORMAT_NV12 ? 2 : 3;
+	tmpclk1 = (1 << 16) * mult - 1;
+	tmpclk2 = (1 << 8) * ((max_dotclk << 8) / crtc_clock);
+	max_scale = min(tmpclk1, tmpclk2);
 
 	return max_scale;
 }
@@ -12920,12 +12942,16 @@ intel_check_primary_plane(struct intel_plane *plane,
 	int max_scale = DRM_PLANE_HELPER_NO_SCALING;
 	bool can_position = false;
 	int ret;
+	uint32_t pixel_format = 0;
 
 	if (INTEL_GEN(dev_priv) >= 9) {
 		/* use scaler when colorkey is not required */
 		if (!state->ckey.flags) {
 			min_scale = 1;
-			max_scale = skl_max_scale(to_intel_crtc(crtc), crtc_state);
+			if (state->base.fb)
+				pixel_format = state->base.fb->format->format;
+			max_scale = skl_max_scale(to_intel_crtc(crtc),
+						  crtc_state, pixel_format);
 		}
 		can_position = true;
 	}

drivers/gpu/drm/i915/intel_drv.h

@@ -552,6 +552,8 @@ struct intel_initial_plane_config {
 #define ICL_MAX_SRC_H 4096
 #define ICL_MAX_DST_W 5120
 #define ICL_MAX_DST_H 4096
+#define SKL_MIN_YUV_420_SRC_W 16
+#define SKL_MIN_YUV_420_SRC_H 16
 
 struct intel_scaler {
 	int in_use;
@@ -1597,7 +1599,8 @@ void intel_mode_from_pipe_config(struct drm_display_mode *mode,
 				 struct intel_crtc_state *pipe_config);
 
 int skl_update_scaler_crtc(struct intel_crtc_state *crtc_state);
-int skl_max_scale(struct intel_crtc *crtc, struct intel_crtc_state *crtc_state);
+int skl_max_scale(struct intel_crtc *crtc, struct intel_crtc_state *crtc_state,
+		  uint32_t pixel_format);
 
 static inline u32 intel_plane_ggtt_offset(const struct intel_plane_state *state)
 {

drivers/gpu/drm/i915/intel_sprite.c

@@ -947,6 +947,7 @@ intel_check_sprite_plane(struct intel_plane *plane,
 	int max_scale, min_scale;
 	bool can_scale;
 	int ret;
+	uint32_t pixel_format = 0;
 
 	*src = drm_plane_state_src(&state->base);
 	*dst = drm_plane_state_dest(&state->base);
@@ -970,11 +971,14 @@ intel_check_sprite_plane(struct intel_plane *plane,
 
 	/* setup can_scale, min_scale, max_scale */
 	if (INTEL_GEN(dev_priv) >= 9) {
+		if (state->base.fb)
+			pixel_format = state->base.fb->format->format;
 		/* use scaler when colorkey is not required */
 		if (!state->ckey.flags) {
 			can_scale = 1;
 			min_scale = 1;
-			max_scale = skl_max_scale(crtc, crtc_state);
+			max_scale =
+				skl_max_scale(crtc, crtc_state, pixel_format);
 		} else {
 			can_scale = 0;
 			min_scale = DRM_PLANE_HELPER_NO_SCALING;