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From 7135599a0b764e3579287763f160d82bb2901c45 Mon Sep 17 00:00:00 2001
From: Dom Cobley <popcornmix@gmail.com>
Date: Fri, 9 Apr 2021 15:00:40 +0100
Subject: [PATCH] vc4/drm: Handle fractional coordinates using the
phase field
Signed-off-by: Dom Cobley <popcornmix@gmail.com>
---
drivers/gpu/drm/vc4/vc4_plane.c | 61 ++++++++++++++++++++++++++++++---
1 file changed, 56 insertions(+), 5 deletions(-)
--- a/drivers/gpu/drm/vc4/vc4_plane.c
+++ b/drivers/gpu/drm/vc4/vc4_plane.c
@@ -458,14 +458,47 @@ static void vc4_write_tpz(struct vc4_pla
VC4_SET_FIELD(recip, SCALER_TPZ1_RECIP));
}
-static void vc4_write_ppf(struct vc4_plane_state *vc4_state, u32 src, u32 dst)
+/* phase magnitude bits */
+#define PHASE_BITS 6
+
+static void vc4_write_ppf(struct vc4_plane_state *vc4_state, u32 src, u32 dst, u32 xy, int channel)
{
- u32 scale = (1 << 16) * src / dst;
+ u32 scale = src / dst;
+ s32 offset, offset2;
+ s32 phase;
+
+ /* Start the phase at 1/2 pixel from the 1st pixel at src_x.
+ 1/4 pixel for YUV. */
+ if (channel) {
+ /* the phase is relative to scale_src->x, so shift it for display list's x value */
+ offset = (xy & 0x1ffff) >> (16 - PHASE_BITS) >> 1;
+ offset += -(1 << PHASE_BITS >> 2);
+ } else {
+ /* the phase is relative to scale_src->x, so shift it for display list's x value */
+ offset = (xy & 0xffff) >> (16 - PHASE_BITS);
+ offset += -(1 << PHASE_BITS >> 1);
+
+ /* This is a kludge to make sure the scaling factors are consitent with YUV's luma scaling.
+ we lose 1bit precision because of this. */
+ scale &= ~1;
+ }
+
+ /* There may be a also small error introduced by precision of scale.
+ Add half of that as a compromise */
+ offset2 = src - dst * scale;
+ offset2 >>= 16 - PHASE_BITS;
+ phase = offset + (offset2 >> 1);
+
+ /* Ensure +ve values don't touch the sign bit, then truncate negative values */
+ if (phase >= 1 << PHASE_BITS)
+ phase = (1 << PHASE_BITS) - 1;
+
+ phase &= SCALER_PPF_IPHASE_MASK;
vc4_dlist_write(vc4_state,
SCALER_PPF_AGC |
VC4_SET_FIELD(scale, SCALER_PPF_SCALE) |
- VC4_SET_FIELD(0, SCALER_PPF_IPHASE));
+ VC4_SET_FIELD(phase, SCALER_PPF_IPHASE));
}
static u32 vc4_lbm_size(struct drm_plane_state *state)
@@ -524,13 +557,13 @@ static void vc4_write_scaling_parameters
/* Ch0 H-PPF Word 0: Scaling Parameters */
if (vc4_state->x_scaling[channel] == VC4_SCALING_PPF) {
vc4_write_ppf(vc4_state,
- vc4_state->src_w[channel], vc4_state->crtc_w);
+ vc4_state->src_w[channel], vc4_state->crtc_w, vc4_state->src_x, channel);
}
/* Ch0 V-PPF Words 0-1: Scaling Parameters, Context */
if (vc4_state->y_scaling[channel] == VC4_SCALING_PPF) {
vc4_write_ppf(vc4_state,
- vc4_state->src_h[channel], vc4_state->crtc_h);
+ vc4_state->src_h[channel], vc4_state->crtc_h, vc4_state->src_y, channel);
vc4_dlist_write(vc4_state, 0xc0c0c0c0);
}
@@ -978,6 +1011,24 @@ static int vc4_plane_mode_set(struct drm
return -EINVAL;
}
+ /* fetch an extra pixel if we don't actually line up with the left edge. */
+ if ((vc4_state->src_x & 0xffff) && vc4_state->src_x < (state->fb->width << 16))
+ width++;
+
+ /* same for the right side */
+ if (((vc4_state->src_x + vc4_state->src_w[0]) & 0xffff) &&
+ vc4_state->src_x + vc4_state->src_w[0] < (state->fb->width << 16))
+ width++;
+
+ /* now for the top */
+ if ((vc4_state->src_y & 0xffff) && vc4_state->src_y < (state->fb->height << 16))
+ height++;
+
+ /* and the bottom */
+ if (((vc4_state->src_y + vc4_state->src_h[0]) & 0xffff) &&
+ vc4_state->src_y + vc4_state->src_h[0] < (state->fb->height << 16))
+ height++;
+
/* Don't waste cycles mixing with plane alpha if the set alpha
* is opaque or there is no per-pixel alpha information.
* In any case we use the alpha property value as the fixed alpha.
|