[Intel-gfx] [PATCH 06/11] 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  | 33 ++++++++++++++++++++++++---------
 3 files changed, 26 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 132640258491..431d07c2aacd 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -12882,7 +12882,7 @@ 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;
 			max_scale = skl_max_scale(to_intel_crtc(crtc), crtc_state);
 		}
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 1a7c5addcec3..b728ac6726b0 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -2027,6 +2027,7 @@ 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 af7470c6bd62..6e4bb721d71c 100644
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/drivers/gpu/drm/i915/intel_sprite.c
@@ -927,6 +927,19 @@ 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,
@@ -968,21 +981,23 @@ 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) {
 		/* use scaler when colorkey is not required */
-		if (!state->ckey.flags) {
-			can_scale = 1;
+		if (!state->ckey.flags && intel_fb_scalable(fb)) {
+			can_scale = true;
 			min_scale = 1;
 			max_scale = skl_max_scale(crtc, crtc_state);
-		} else {
-			can_scale = 0;
-			min_scale = DRM_PLANE_HELPER_NO_SCALING;
-			max_scale = DRM_PLANE_HELPER_NO_SCALING;
 		}
 	} 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);
+		}
 	}
 
 	/*
-- 
2.16.1