diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 749d238117490f88cfcfd23c88e90c9d13443982..43397e50fec371a9c057a015f846ce6b6b48ad95 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -6789,6 +6789,10 @@ enum {
#define _PS_VPHASE_1B 0x68988
#define _PS_VPHASE_2B 0x68A88
#define _PS_VPHASE_1C 0x69188
+#define PS_Y_PHASE(x) ((x) << 16)
+#define PS_UV_RGB_PHASE(x) ((x) << 0)
+#define PS_PHASE_MASK (0x7fff << 1) /* u2.13 */
+#define PS_PHASE_TRIP (1 << 0)
#define _PS_HPHASE_1A 0x68194
#define _PS_HPHASE_2A 0x68294
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index b422312804185544c135dc6bdc955f2e592720d1..141ded52448203b92f94ac4b1324efe393afa85f 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4752,6 +4752,39 @@ static void cpt_verify_modeset(struct drm_device *dev, int pipe)
}
}
+/*
+ * The hardware phase 0.0 refers to the center of the pixel.
+ * We want to start from the top/left edge which is phase
+ * -0.5. That matches how the hardware calculates the scaling
+ * factors (from top-left of the first pixel to bottom-right
+ * of the last pixel, as opposed to the pixel centers).
+ *
+ * For 4:2:0 subsampled chroma planes we obviously have to
+ * adjust that so that the chroma sample position lands in
+ * the right spot.
+ *
+ * Note that for packed YCbCr 4:2:2 formats there is no way to
+ * control chroma siting. The hardware simply replicates the
+ * chroma samples for both of the luma samples, and thus we don't
+ * actually get the expected MPEG2 chroma siting convention :(
+ * The same behaviour is observed on pre-SKL platforms as well.
+ */
+u16 skl_scaler_calc_phase(int sub, bool chroma_cosited)
+{
+ int phase = -0x8000;
+ u16 trip = 0;
+
+ if (chroma_cosited)
+ phase += (sub - 1) * 0x8000 / sub;
+
+ if (phase < 0)
+ phase = 0x10000 + phase;
+ else
+ trip = PS_PHASE_TRIP;
+
+ return ((phase >> 2) & PS_PHASE_MASK) | trip;
+}
+
static int
skl_update_scaler(struct intel_crtc_state *crtc_state, bool force_detach,
unsigned int scaler_user, int *scaler_id,
@@ -4951,14 +4984,22 @@ static void skylake_pfit_enable(struct intel_crtc *crtc)
&crtc->config->scaler_state;
if (crtc->config->pch_pfit.enabled) {
+ u16 uv_rgb_hphase, uv_rgb_vphase;
int id;
if (WARN_ON(crtc->config->scaler_state.scaler_id < 0))
return;
+ uv_rgb_hphase = skl_scaler_calc_phase(1, false);
+ uv_rgb_vphase = skl_scaler_calc_phase(1, false);
+
id = scaler_state->scaler_id;
I915_WRITE(SKL_PS_CTRL(pipe, id), PS_SCALER_EN |
PS_FILTER_MEDIUM | scaler_state->scalers[id].mode);
+ I915_WRITE_FW(SKL_PS_VPHASE(pipe, id),
+ PS_Y_PHASE(0) | PS_UV_RGB_PHASE(uv_rgb_vphase));
+ I915_WRITE_FW(SKL_PS_HPHASE(pipe, id),
+ PS_Y_PHASE(0) | PS_UV_RGB_PHASE(uv_rgb_hphase));
I915_WRITE(SKL_PS_WIN_POS(pipe, id), crtc->config->pch_pfit.pos);
I915_WRITE(SKL_PS_WIN_SZ(pipe, id), crtc->config->pch_pfit.size);
}
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 1a4659a2e000a89d2943602ef2d0b374498cb61e..b1bb1a9d61f824839e159590ce8c1c3904b10423 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1616,6 +1616,7 @@ void intel_mode_from_pipe_config(struct drm_display_mode *mode,
void intel_crtc_arm_fifo_underrun(struct intel_crtc *crtc,
struct intel_crtc_state *crtc_state);
+u16 skl_scaler_calc_phase(int sub, bool chroma_center);
int skl_update_scaler_crtc(struct intel_crtc_state *crtc_state);
int skl_max_scale(struct intel_crtc *crtc, struct intel_crtc_state *crtc_state,
uint32_t pixel_format);
diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
index 350c61cfd1e7108756aa32dbad32bc65026e1062..24f86c4375cf93e7695ec7cb076c8ad2987607d3 100644
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/drivers/gpu/drm/i915/intel_sprite.c
@@ -284,13 +284,35 @@ skl_update_plane(struct intel_plane *plane,
/* program plane scaler */
if (plane_state->scaler_id >= 0) {
int scaler_id = plane_state->scaler_id;
- const struct intel_scaler *scaler;
+ const struct intel_scaler *scaler =
+ &crtc_state->scaler_state.scalers[scaler_id];
+ u16 y_hphase, uv_rgb_hphase;
+ u16 y_vphase, uv_rgb_vphase;
+
+ /* TODO: handle sub-pixel coordinates */
+ if (fb->format->format == DRM_FORMAT_NV12) {
+ y_hphase = skl_scaler_calc_phase(1, false);
+ y_vphase = skl_scaler_calc_phase(1, false);
+
+ /* MPEG2 chroma siting convention */
+ uv_rgb_hphase = skl_scaler_calc_phase(2, true);
+ uv_rgb_vphase = skl_scaler_calc_phase(2, false);
+ } else {
+ /* not used */
+ y_hphase = 0;
+ y_vphase = 0;
- scaler = &crtc_state->scaler_state.scalers[scaler_id];
+ uv_rgb_hphase = skl_scaler_calc_phase(1, false);
+ uv_rgb_vphase = skl_scaler_calc_phase(1, false);
+ }
I915_WRITE_FW(SKL_PS_CTRL(pipe, scaler_id),
PS_SCALER_EN | PS_PLANE_SEL(plane_id) | scaler->mode);
I915_WRITE_FW(SKL_PS_PWR_GATE(pipe, scaler_id), 0);
+ I915_WRITE_FW(SKL_PS_VPHASE(pipe, scaler_id),
+ PS_Y_PHASE(y_vphase) | PS_UV_RGB_PHASE(uv_rgb_vphase));
+ I915_WRITE_FW(SKL_PS_HPHASE(pipe, scaler_id),
+ PS_Y_PHASE(y_hphase) | PS_UV_RGB_PHASE(uv_rgb_hphase));
I915_WRITE_FW(SKL_PS_WIN_POS(pipe, scaler_id), (crtc_x << 16) | crtc_y);
I915_WRITE_FW(SKL_PS_WIN_SZ(pipe, scaler_id),
((crtc_w + 1) << 16)|(crtc_h + 1));