From: Suraj Kandpal <[email protected]> Hook the per-lane TxFFE state added by the previous patch into the HDMI FRL Link Training Sequence (LTS:3):
- Advertise FFE_Levels=3 (TxFFE0..TxFFE3) in SCDC 0x31, matching the four TxFFE rows present in the PHY HDMI FRL buf-trans table. - On LTS:3 entry, after enabling TRANS_HDMI_FRL_ENABLE, call encoder->set_signal_levels() so the PHY is programmed to TxFFE0 on every lane before the sink starts emitting Ln(x)_LTP_req. - In intel_hdmi_train_lanes(), handle SCDC_FRL_CHNG_FFE (0xE) by incrementing intel_hdmi->frl.ffe_level[lane], capped at max_ffe_level. When any lane changed, reprogram the PHY via encoder->set_signal_levels() before acknowledging the request. - Always clear SCDC FLT_update (0x10 bit 5) after acting on a sink request, as required by the HDMI spec. A forward declaration of clear_scdc_update_flags() is added so it can be called from intel_hdmi_train_lanes() without reordering the file. Signed-off-by: Suraj Kandpal <[email protected]> --- drivers/gpu/drm/i915/display/intel_hdmi.c | 39 +++++++++++++++++++---- 1 file changed, 32 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c index ba1543023373..db585c2af21d 100644 --- a/drivers/gpu/drm/i915/display/intel_hdmi.c +++ b/drivers/gpu/drm/i915/display/intel_hdmi.c @@ -3573,6 +3573,7 @@ static int clear_scdc_update_flags(struct intel_encoder *encoder, u8 flags) static bool intel_hdmi_frl_prepare_lts2(struct intel_encoder *encoder, + const struct intel_crtc_state *crtc_state, int frl_rate, int frl_lanes, int ffe_level) { @@ -3598,7 +3599,12 @@ intel_hdmi_frl_prepare_lts2(struct intel_encoder *encoder, if ((get_frl_update_flags(encoder) & SCDC_FLT_UPDATE)) clear_scdc_update_flags(encoder, SCDC_FLT_UPDATE); - /* #TODO: Source shall program TxFFE = 0 for all active lanes */ + /* + * Program PHY to TxFFE0 on every lane before the sink + * starts evaluating LTP patterns. ffe_level[] has already been + * cleared by intel_hdmi_reset_frl_config(). + */ + encoder->set_signal_levels(encoder, crtc_state); if (drm_scdc_config_frl(adapter, frl_rate, frl_lanes, ffe_level) < 0) { drm_dbg_kms(display->drm, @@ -3633,9 +3639,11 @@ intel_hdmi_train_lanes(struct intel_encoder *encoder, int ffe_level) { struct intel_display *display = to_intel_display(encoder); + struct intel_hdmi *intel_hdmi = enc_to_intel_hdmi(encoder); enum transcoder trans = crtc_state->cpu_transcoder; int num_lanes = crtc_state->frl.required_lanes; enum drm_scdc_frl_ltp ltp[4]; + bool ffe_changed = false; u32 write_buf = 0; int lane; @@ -3657,13 +3665,29 @@ intel_hdmi_train_lanes(struct intel_encoder *encoder, for (lane = 0; lane < num_lanes; lane++) { if (ltp[lane] >= SCDC_FRL_LTP1 && ltp[lane] <= SCDC_FRL_LTP8) write_buf |= TRANS_HDMI_FRL_LTP(ltp[lane], lane); - /* #TODO handle FFE change */ - else if (ltp[lane] == SCDC_FRL_CHNG_FFE) - continue; + else if (ltp[lane] == SCDC_FRL_CHNG_FFE) { + /* + * During FRL link training: Sink requests Source + * to step TxFFE up by one for this lane. Cap at the + * advertised max FFE level. + */ + if (intel_hdmi->frl.ffe_level[lane] < + intel_hdmi->frl.max_ffe_level) { + intel_hdmi->frl.ffe_level[lane]++; + ffe_changed = true; + } + } } intel_de_write(display, TRANS_HDMI_FRL_TRAIN(display, trans), write_buf); + /* + * Reprogram per-lane PHY TxFFE before clearing FLT_update so the + * sink evaluates the new preset on the next iteration. + */ + if (ffe_changed) + encoder->set_signal_levels(encoder, crtc_state); + clear_scdc_update_flags(encoder, SCDC_FLT_UPDATE); return FRL_TRAIN_CONTINUE; @@ -3752,9 +3776,9 @@ static int get_next_frl_rate(int curr_rate_gbps) return -EINVAL; } -static int get_ffe_level(int rate_gbps) +static int get_max_ffe_level(int rate_gbps) { - return 0; + return 3; } int intel_hdmi_start_frl(struct intel_encoder *encoder, @@ -3766,7 +3790,7 @@ int intel_hdmi_start_frl(struct intel_encoder *encoder, struct intel_connector *intel_connector = intel_hdmi->attached_connector; struct drm_connector *connector = &intel_connector->base; int req_rate = crtc_state->frl.required_lanes * crtc_state->frl.required_rate; - int ffe_level = get_ffe_level(req_rate); + int ffe_level = get_max_ffe_level(req_rate); enum frl_lt_status status; int next_rate = -EINVAL; @@ -3786,6 +3810,7 @@ int intel_hdmi_start_frl(struct intel_encoder *encoder, intel_hdmi->frl.max_ffe_level = ffe_level; if (!intel_hdmi_frl_prepare_lts2(encoder, + crtc_state, crtc_state->frl.required_rate, crtc_state->frl.required_lanes, ffe_level)) -- 2.50.1
