[Intel-gfx] [PATCH v2 06/13] drm/i915: Disallow plane scaling with specific pixel formats

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

Plane scaling is not supported with specific pixel formats. Disallow
plane scaling when such a format is used. Currently the only such
pixel format we expose is C8, but in case we add more in the future
let's make it easy to deal with them.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_display.c |  2 +-
 drivers/gpu/drm/i915/intel_drv.h     |  1 +
 drivers/gpu/drm/i915/intel_sprite.c  | 41 ++++++++++++++++++++++++------------
 3 files changed, 29 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index c9ed32d7b869..453ea548fbd1 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -13034,7 +13034,7 @@ intel_check_primary_plane(struct intel_plane *plane,
 
 	if (INTEL_GEN(dev_priv) >= 9) {
 		/* use scaler when colorkey is not required */
-		if (!state->ckey.flags) {
+		if (!state->ckey.flags && intel_fb_scalable(state->base.fb)) {
 			min_scale = 1;
 			if (state->base.fb)
 				pixel_format = state->base.fb->format->format;
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index fd6256632482..e39827b5da5f 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -2070,6 +2070,7 @@ bool intel_sdvo_init(struct drm_i915_private *dev_priv,
 
 /* intel_sprite.c */
 bool intel_format_is_yuv(u32 format);
+bool intel_fb_scalable(const struct drm_framebuffer *fb);
 int intel_usecs_to_scanlines(const struct drm_display_mode *adjusted_mode,
 			     int usecs);
 struct intel_plane *intel_sprite_plane_create(struct drm_i915_private *dev_priv,
diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
index 2ce3ffbf8ab1..73a74e6ef847 100644
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/drivers/gpu/drm/i915/intel_sprite.c
@@ -928,6 +928,19 @@ g4x_plane_get_hw_state(struct intel_plane *plane)
 	return ret;
 }
 
+bool intel_fb_scalable(const struct drm_framebuffer *fb)
+{
+	if (!fb)
+		return false;
+
+	switch (fb->format->format) {
+	case DRM_FORMAT_C8:
+		return false;
+	default:
+		return true;
+	}
+}
+
 static int
 intel_check_sprite_plane(struct intel_plane *plane,
 			 struct intel_crtc_state *crtc_state,
@@ -940,7 +953,6 @@ intel_check_sprite_plane(struct intel_plane *plane,
 	int max_scale, min_scale;
 	bool can_scale;
 	int ret;
-	uint32_t pixel_format = 0;
 
 	if (!fb) {
 		state->base.visible = false;
@@ -960,24 +972,25 @@ intel_check_sprite_plane(struct intel_plane *plane,
 	}
 
 	/* setup can_scale, min_scale, max_scale */
+	can_scale = false;
+	min_scale = DRM_PLANE_HELPER_NO_SCALING;
+	max_scale = DRM_PLANE_HELPER_NO_SCALING;
+
 	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;
+		if (!state->ckey.flags && intel_fb_scalable(fb)) {
+			u32 pixel_format = fb ? fb->format->format : 0;
+
+			can_scale = true;
 			min_scale = 1;
-			max_scale =
-				skl_max_scale(crtc, crtc_state, pixel_format);
-		} else {
-			can_scale = 0;
-			min_scale = DRM_PLANE_HELPER_NO_SCALING;
-			max_scale = DRM_PLANE_HELPER_NO_SCALING;
+			max_scale = skl_max_scale(crtc, crtc_state, pixel_format);
 		}
 	} else {
-		can_scale = plane->can_scale;
-		max_scale = plane->max_downscale << 16;
-		min_scale = plane->can_scale ? 1 : (1 << 16);
+		if (intel_fb_scalable(fb)) {
+			can_scale = plane->can_scale;
+			max_scale = plane->max_downscale << 16;
+			min_scale = plane->can_scale ? 1 : (1 << 16);
+		}
 	}
 
 	ret = drm_atomic_helper_check_plane_state(&state->base,
-- 
2.16.1