If the sink requests a rate change during FRL Link training, reduce frl.rate_cap to the next lower FRL rate. The next mode compute then uses this lower rate cap, so we do not attempt the failing rate again.
Signed-off-by: Ankit Nautiyal <[email protected]> --- drivers/gpu/drm/i915/display/intel_hdmi.c | 27 ++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c index fe4923c82463..2b0cdb0719e2 100644 --- a/drivers/gpu/drm/i915/display/intel_hdmi.c +++ b/drivers/gpu/drm/i915/display/intel_hdmi.c @@ -3720,6 +3720,18 @@ intel_hdmi_frl_train_lts3(struct intel_encoder *encoder, return frl_train_complete_ltsp(encoder, crtc_state); } +static int get_next_frl_rate(int curr_rate_gbps) +{ + int valid_rate[] = { 48, 40, 32, 24, 18, 9 }; + int i; + + for (i = 0; i < ARRAY_SIZE(valid_rate); i++) + if (valid_rate[i] < curr_rate_gbps) + return valid_rate[i]; + + return -EINVAL; +} + static int get_ffe_level(int rate_gbps) { return 0; @@ -3736,6 +3748,7 @@ int intel_hdmi_start_frl(struct intel_encoder *encoder, int req_rate = crtc_state->frl.required_lanes * crtc_state->frl.required_rate; int ffe_level = get_ffe_level(req_rate); enum frl_lt_status status; + int next_rate = -EINVAL; if (!crtc_state->frl.enable) return 0; @@ -3769,10 +3782,22 @@ int intel_hdmi_start_frl(struct intel_encoder *encoder, connector->base.id, connector->name, intel_hdmi->frl.rate_gbps); return 0; - default: + case FRL_TRAIN_STOP: + next_rate = 0; + break; + case FRL_CHANGE_RATE: + next_rate = get_next_frl_rate(req_rate); break; + case FRL_TRAIN_RETRAIN: + fallthrough; + default: + goto ltsl_tmds_mode; } + if (next_rate >= 0) + intel_hdmi->frl.rate_cap = next_rate; + +ltsl_tmds_mode: if (crtc_state->frl.enable && !intel_hdmi->frl.trained) drm_err(display->drm, "[CONNECTOR:%d:%s] FRL Training Failed with rate=%d\n", -- 2.50.1
