Mandate a minimum Hblank symbol cycle count between BS and BE in 8b/10b MST and 12b/132b mode. Spec: DP2.1a
Signed-off-by: Arun R Murthy <[email protected]> --- drivers/gpu/drm/i915/display/intel_display.c | 6 ++++++ drivers/gpu/drm/i915/display/intel_display_types.h | 1 + drivers/gpu/drm/i915/display/intel_dp_mst.c | 9 +++++++++ drivers/gpu/drm/i915/i915_reg.h | 3 +++ 4 files changed, 19 insertions(+) diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c index 78ce402a5cd0..027ab45d4d38 100644 --- a/drivers/gpu/drm/i915/display/intel_display.c +++ b/drivers/gpu/drm/i915/display/intel_display.c @@ -2095,6 +2095,7 @@ void intel_modeset_put_crtc_power_domains(struct intel_crtc *crtc, static void i9xx_configure_cpu_transcoder(const struct intel_crtc_state *crtc_state) { struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc); + struct drm_i915_private *i915 = to_i915(crtc->base.dev); enum transcoder cpu_transcoder = crtc_state->cpu_transcoder; if (intel_crtc_has_dp_encoder(crtc_state)) { @@ -2102,6 +2103,11 @@ static void i9xx_configure_cpu_transcoder(const struct intel_crtc_state *crtc_st &crtc_state->dp_m_n); intel_cpu_transcoder_set_m2_n2(crtc, cpu_transcoder, &crtc_state->dp_m2_n2); + + if (DISPLAY_VER(i915) >= 20 && crtc_state->dp_m_n.min_hblank) + intel_de_write(i915, + DP_MIN_HBLANK_CTL(i915, cpu_transcoder), + crtc_state->dp_m_n.min_hblank); } intel_set_transcoder_timings(crtc_state); diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h index fa03157554b2..8d18545a369f 100644 --- a/drivers/gpu/drm/i915/display/intel_display_types.h +++ b/drivers/gpu/drm/i915/display/intel_display_types.h @@ -1028,6 +1028,7 @@ struct intel_link_m_n { u32 data_n; u32 link_m; u32 link_n; + u32 min_hblank; }; struct intel_csc_matrix { diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c index 15541932b809..c8f045142881 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c @@ -130,6 +130,8 @@ static void intel_dp_mst_compute_m_n(const struct intel_crtc_state *crtc_state, { const struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode; + u8 symbol_size = intel_dp_is_uhbr(crtc_state) ? 32 : 8; + u32 hblank; /* TODO: Check WA 14013163432 to set data M/N for full BW utilization. */ intel_link_compute_m_n(bpp_x16, crtc_state->lane_count, @@ -139,6 +141,13 @@ static void intel_dp_mst_compute_m_n(const struct intel_crtc_state *crtc_state, m_n); m_n->tu = DIV_ROUND_UP_ULL(mul_u32_u32(m_n->data_m, 64), m_n->data_n); + + /* Calculate min Hblank Link Layer Symbol Cycle Count for 8b/10b MST & 128b/132b */ + hblank = DIV_ROUND_UP((DIV_ROUND_UP(adjusted_mode->htotal - adjusted_mode->hdisplay, 4) * bpp_x16), symbol_size); + if (intel_dp_is_uhbr(crtc_state)) + m_n->min_hblank = hblank > 5 ? hblank : 5; + else + m_n->min_hblank = hblank > 3 ? hblank : 3; } static int intel_dp_mst_calc_pbn(int pixel_clock, int bpp_x16, int bw_overhead) diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 41f4350a7c6c..65133efe728c 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -1109,6 +1109,7 @@ #define _BCLRPAT_A 0x60020 #define _TRANS_VSYNCSHIFT_A 0x60028 #define _TRANS_MULT_A 0x6002c +#define _DP_MIN_HBLANK_CTL_A 0x600ac /* Pipe/transcoder B timing regs */ #define _TRANS_HTOTAL_B 0x61000 @@ -1121,6 +1122,7 @@ #define _BCLRPAT_B 0x61020 #define _TRANS_VSYNCSHIFT_B 0x61028 #define _TRANS_MULT_B 0x6102c +#define _DP_MIN_HBLANK_CTL_B 0x610ac /* DSI 0 timing regs */ #define _TRANS_HTOTAL_DSI0 0x6b000 @@ -1146,6 +1148,7 @@ #define TRANS_VSYNCSHIFT(dev_priv, trans) _MMIO_TRANS2(dev_priv, (trans), _TRANS_VSYNCSHIFT_A) #define PIPESRC(dev_priv, pipe) _MMIO_TRANS2(dev_priv, (pipe), _PIPEASRC) #define TRANS_MULT(dev_priv, trans) _MMIO_TRANS2(dev_priv, (trans), _TRANS_MULT_A) +#define DP_MIN_HBLANK_CTL(dev_priv, trans) _MMIO_TRANS2(dev_priv, (trans), _DP_MIN_HBLANK_CTL_A) /* VGA port control */ #define ADPA _MMIO(0x61100) -- 2.25.1
