[Intel-gfx] [PATCH 4/8] drm/i915/skl+: Use scaling amount for plane data rate calculation (v3)

[Matt Roper]

From: "Kumar, Mahesh" <mahesh1.kumar at intel.com>

if downscaling is enabled plane data rate increases according to scaling
amount. take scaling amount under consideration while calculating plane
data rate

v2: Address Matt's comments, where data rate was overridden because of
missing else.

v3 (by Matt):
 - Add braces to 'else' branch to match kernel coding style
 - Adjust final calculation now that skl_plane_downscale_amount()
   returns 16.16 fixed point value instead of a decimal fixed point

Cc: matthew.d.roper at intel.com
Signed-off-by: Kumar, Mahesh <mahesh1.kumar at intel.com>
Reviewed-by(v2): Matt Roper <matthew.d.roper at intel.com>
Signed-off-by: Matt Roper <matthew.d.roper at intel.com>
---
 drivers/gpu/drm/i915/intel_pm.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index e828bde..041db5d3 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -2974,6 +2974,8 @@ skl_plane_relative_data_rate(const struct intel_crtc_state *cstate,
 {
 	struct intel_plane_state *intel_pstate = to_intel_plane_state(pstate);
 	struct drm_framebuffer *fb = pstate->fb;
+	struct intel_plane *intel_plane = to_intel_plane(pstate->plane);
+	uint32_t down_scale_amount, data_rate;
 	uint32_t width = 0, height = 0;
 
 	width = drm_rect_width(&intel_pstate->src) >> 16;
@@ -2985,15 +2987,20 @@ skl_plane_relative_data_rate(const struct intel_crtc_state *cstate,
 	/* for planar format */
 	if (fb->pixel_format == DRM_FORMAT_NV12) {
 		if (y)  /* y-plane data rate */
-			return width * height *
+			data_rate = width * height *
 				drm_format_plane_cpp(fb->pixel_format, 0);
 		else    /* uv-plane data rate */
-			return (width / 2) * (height / 2) *
+			data_rate = (width / 2) * (height / 2) *
 				drm_format_plane_cpp(fb->pixel_format, 1);
+	} else {
+		/* for packed formats */
+		data_rate = width * height *
+			drm_format_plane_cpp(fb->pixel_format, 0);
 	}
 
-	/* for packed formats */
-	return width * height * drm_format_plane_cpp(fb->pixel_format, 0);
+	down_scale_amount = skl_plane_downscale_amount(intel_plane);
+
+	return data_rate * down_scale_amount >> 16;
 }
 
 /*
-- 
2.1.4