From 3941a9b88283f442b5af2c5bb843698eef86c58a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@linux.intel.com>
Date: Tue, 18 Jan 2022 11:23:42 +0200
Subject: drm/i915: Fix plane relative_data_rate calculation
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Git-commit: 759d4fff3d2d70d6b689a9f1f7eb4488df337fbd
Patch-mainline: v5.18-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225
We are currently computing the relative data rates as
src_size * scale_factor where scale_factor is src_size / dst_size.
Thus relative data rate is src_size * src_size / dst_size,
which is just utter nonsense. What we really seem to want is
just a reasonable estimate on how much data will be fetched
which is just src_size. So let's do that instead.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220118092354.11631-4-ville.syrjala@linux.intel.com
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/i915/intel_pm.c | 63 ++-------------------------------
1 file changed, 2 insertions(+), 61 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 3ef57c210e79..2515d257530c 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -4356,55 +4356,6 @@ void skl_pipe_ddb_get_hw_state(struct intel_crtc *crtc,
intel_display_power_put(dev_priv, power_domain, wakeref);
}
-/*
- * Determines the downscale amount of a plane for the purposes of watermark calculations.
- * The bspec defines downscale amount as:
- *
- * """
- * Horizontal down scale amount = maximum[1, Horizontal source size /
- * Horizontal destination size]
- * Vertical down scale amount = maximum[1, Vertical source size /
- * Vertical destination size]
- * Total down scale amount = Horizontal down scale amount *
- * Vertical down scale amount
- * """
- *
- * Return value is provided in 16.16 fixed point form to retain fractional part.
- * Caller should take care of dividing & rounding off the value.
- */
-static uint_fixed_16_16_t
-skl_plane_downscale_amount(const struct intel_crtc_state *crtc_state,
- const struct intel_plane_state *plane_state)
-{
- struct drm_i915_private *dev_priv = to_i915(crtc_state->uapi.crtc->dev);
- u32 src_w, src_h, dst_w, dst_h;
- uint_fixed_16_16_t fp_w_ratio, fp_h_ratio;
- uint_fixed_16_16_t downscale_h, downscale_w;
-
- if (drm_WARN_ON(&dev_priv->drm,
- !intel_wm_plane_visible(crtc_state, plane_state)))
- return u32_to_fixed16(0);
-
- /*
- * Src coordinates are already rotated by 270 degrees for
- * the 90/270 degree plane rotation cases (to match the
- * GTT mapping), hence no need to account for rotation here.
- *
- * n.b., src is 16.16 fixed point, dst is whole integer.
- */
- src_w = drm_rect_width(&plane_state->uapi.src) >> 16;
- src_h = drm_rect_height(&plane_state->uapi.src) >> 16;
- dst_w = drm_rect_width(&plane_state->uapi.dst);
- dst_h = drm_rect_height(&plane_state->uapi.dst);
-
- fp_w_ratio = div_fixed16(src_w, dst_w);
- fp_h_ratio = div_fixed16(src_h, dst_h);
- downscale_w = max_fixed16(fp_w_ratio, u32_to_fixed16(1));
- downscale_h = max_fixed16(fp_h_ratio, u32_to_fixed16(1));
-
- return mul_fixed16(downscale_w, downscale_h);
-}
-
struct dbuf_slice_conf_entry {
u8 active_pipes;
u8 dbuf_mask[I915_MAX_PIPES];
@@ -4960,10 +4911,7 @@ skl_plane_relative_data_rate(const struct intel_crtc_state *crtc_state,
{
struct intel_plane *plane = to_intel_plane(plane_state->uapi.plane);
const struct drm_framebuffer *fb = plane_state->hw.fb;
- u32 data_rate;
- u32 width = 0, height = 0;
- uint_fixed_16_16_t down_scale_amount;
- u64 rate;
+ int width, height;
if (!plane_state->uapi.visible)
return 0;
@@ -4997,14 +4945,7 @@ skl_plane_relative_data_rate(const struct intel_crtc_state *crtc_state,
height /= 2;
}
- data_rate = width * height;
-
- down_scale_amount = skl_plane_downscale_amount(crtc_state, plane_state);
-
- rate = mul_round_up_u32_fixed16(data_rate, down_scale_amount);
-
- rate *= fb->format->cpp[color_plane];
- return rate;
+ return width * height * fb->format->cpp[color_plane];
}
static u64
--
2.38.1