[Intel-gfx] [PATCH] drm/i915/skl: Use proper plane dimensions for DDB and WM calculations

[Matt Roper]

In commit

        commit 024c9045221fe45482863c47c4b4c47d37f97cbf
        Author: Matt Roper <matthew.d.roper at intel.com>
        Date:   Thu Sep 24 15:53:11 2015 -0700

            drm/i915/skl: Eliminate usage of pipe_wm_parameters from SKL-style WM (v4)

I fumbled while converting the dimensions stored in the plane_parameters
structure to the values stored in plane state and accidentally replaced
the plane dimensions with the pipe dimensions in both the DDB allocation
function and the WM calculation function.  On the DDB side this is
harmless since we effectively treat all of our non-cursor planes as
full-screen which may not be optimal, but generally won't cause any
problems either (and in 99% of the cases where there's no sprite plane
usage or primary plane windowing, there's no effect at all).  On the WM
calculation side there's more potential for this fumble to cause actual
problems since cursors also get miscalculated.

Cc: Ville Syrjälä <ville.syrjala at intel.com>
Cc: "Kondapally, Kalyan" <kalyan.kondapally at intel.com>
Cc: Radhakrishna Sripada <radhakrishna.sripada at intel.com>
Signed-off-by: Matt Roper <matthew.d.roper at intel.com>
---
 drivers/gpu/drm/i915/intel_pm.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 8d0d6f5..f4d4cc7 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -2845,25 +2845,22 @@ skl_plane_relative_data_rate(const struct intel_crtc_state *cstate,
 			     const struct drm_plane_state *pstate,
 			     int y)
 {
-	struct intel_crtc *intel_crtc = to_intel_crtc(cstate->base.crtc);
+	struct intel_plane_state *intel_pstate = to_intel_plane_state(pstate);
 	struct drm_framebuffer *fb = pstate->fb;
+	unsigned w = drm_rect_width(&intel_pstate->dst);
+	unsigned h = drm_rect_height(&intel_pstate->dst);
 
 	/* for planar format */
 	if (fb->pixel_format == DRM_FORMAT_NV12) {
 		if (y)  /* y-plane data rate */
-			return intel_crtc->config->pipe_src_w *
-				intel_crtc->config->pipe_src_h *
-				drm_format_plane_cpp(fb->pixel_format, 0);
+			return w * h * drm_format_plane_cpp(fb->pixel_format, 0);
 		else    /* uv-plane data rate */
-			return (intel_crtc->config->pipe_src_w/2) *
-				(intel_crtc->config->pipe_src_h/2) *
+			return (w/2) * (h/2) *
 				drm_format_plane_cpp(fb->pixel_format, 1);
 	}
 
 	/* for packed formats */
-	return intel_crtc->config->pipe_src_w *
-		intel_crtc->config->pipe_src_h *
-		drm_format_plane_cpp(fb->pixel_format, 0);
+	return w * h * drm_format_plane_cpp(fb->pixel_format, 0);
 }
 
 /*
@@ -2960,6 +2957,8 @@ skl_allocate_pipe_ddb(struct intel_crtc_state *cstate,
 	 * FIXME: we may not allocate every single block here.
 	 */
 	total_data_rate = skl_get_total_relative_data_rate(cstate);
+	if (!total_data_rate)
+		return;
 
 	start = alloc->start;
 	for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
@@ -3093,12 +3092,15 @@ static bool skl_compute_plane_wm(const struct drm_i915_private *dev_priv,
 {
 	struct drm_plane *plane = &intel_plane->base;
 	struct drm_framebuffer *fb = plane->state->fb;
+	struct intel_plane_state *intel_pstate =
+		to_intel_plane_state(plane->state);
 	uint32_t latency = dev_priv->wm.skl_latency[level];
 	uint32_t method1, method2;
 	uint32_t plane_bytes_per_line, plane_blocks_per_line;
 	uint32_t res_blocks, res_lines;
 	uint32_t selected_result;
 	uint8_t bytes_per_pixel;
+	unsigned w = drm_rect_width(&intel_pstate->dst);
 
 	if (latency == 0 || !cstate->base.active || !fb)
 		return false;
@@ -3109,12 +3111,12 @@ static bool skl_compute_plane_wm(const struct drm_i915_private *dev_priv,
 				 latency);
 	method2 = skl_wm_method2(skl_pipe_pixel_rate(cstate),
 				 cstate->base.adjusted_mode.crtc_htotal,
-				 cstate->pipe_src_w,
+				 w,
 				 bytes_per_pixel,
 				 fb->modifier[0],
 				 latency);
 
-	plane_bytes_per_line = cstate->pipe_src_w * bytes_per_pixel;
+	plane_bytes_per_line = w * bytes_per_pixel;
 	plane_blocks_per_line = DIV_ROUND_UP(plane_bytes_per_line, 512);
 
 	if (fb->modifier[0] == I915_FORMAT_MOD_Y_TILED ||
-- 
2.1.4