DP2.1 ALPM is not supported on UHBR (128b/132b) link rates on the NVL platform. Reject the ALPM parameter computation for external DP running at a UHBR rate on display version 35, so that ALPM (and the Panel Replay and LOBF features that rely on it) is not enabled in that case. eDP is excluded so eDP ALPM keeps working at any link rate.
Cc: Jouni Högander <[email protected]> Signed-off-by: Animesh Manna <[email protected]> --- drivers/gpu/drm/i915/display/intel_alpm.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/gpu/drm/i915/display/intel_alpm.c b/drivers/gpu/drm/i915/display/intel_alpm.c index 84777c8d31bb..51805a6bca86 100644 --- a/drivers/gpu/drm/i915/display/intel_alpm.c +++ b/drivers/gpu/drm/i915/display/intel_alpm.c @@ -453,6 +453,12 @@ bool intel_alpm_compute_params(struct intel_dp *intel_dp, int precharge = intel_dp_aux_fw_sync_len(intel_dp) - preamble; u8 max_wake_lines; + /* DP2.1 ALPM is not supported on UHBR (128b/132b) link rates on NVL. */ + if (DISPLAY_VER(display) == 35 && + !intel_crtc_has_type(crtc_state, INTEL_OUTPUT_EDP) && + intel_dp_is_uhbr(crtc_state)) + return false; + io_wake_time = max(precharge, io_buffer_wake_time(crtc_state)) + preamble + phy_wake + tfw_exit_latency; fast_wake_time = precharge + preamble + phy_wake + -- 2.29.0
