[PATCH v2 05/10] drm/i915/alpm: Auxless wake time calculation for Xe3p
From: Animesh Manna <hidden>
Date: 2025-11-03 22:37:38
Also in:
intel-gfx, intel-xe
Subsystem:
drm drivers, intel drm display for xe and i915 drivers, intel drm i915 driver (meteor lake, dg2 and older excluding poulsbo, moorestown and derivative), the rest · Maintainers:
David Airlie, Simona Vetter, Jani Nikula, Rodrigo Vivi, Joonas Lahtinen, Tvrtko Ursulin, Linus Torvalds
Add support for auxless waketime calculation for DP2.1 ALPM as dependent parameter got changed. v1: Initial version. v2: Use intel_dp_is_uhbr(). [Jani] Cc: Jouni Högander <redacted> Signed-off-by: Animesh Manna <redacted> --- drivers/gpu/drm/i915/display/intel_alpm.c | 51 ++++++++++++++++++++--- 1 file changed, 46 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_alpm.c b/drivers/gpu/drm/i915/display/intel_alpm.c
index 8d07455a62c2..5686064def8d 100644
--- a/drivers/gpu/drm/i915/display/intel_alpm.c
+++ b/drivers/gpu/drm/i915/display/intel_alpm.c@@ -87,7 +87,9 @@ static int get_lfps_half_cycle_clocks(const struct intel_crtc_state *crtc_state) static int get_tphy2_p2_to_p0(struct intel_dp *intel_dp) { - return 12 * 1000; + struct intel_display *display = to_intel_display(intel_dp); + + return DISPLAY_VER(display) >= 35 ? (40 * 1000) : (12 * 1000); } static int get_establishment_period(struct intel_dp *intel_dp,
@@ -95,16 +97,54 @@ static int get_establishment_period(struct intel_dp *intel_dp, { int port_clock = crtc_state->port_clock; int t1 = 50 * 1000; - int tps4 = (252 * 10); + int tps4 = intel_dp_is_uhbr(crtc_state) ? (396 * 32) : (252 * 10); long tml_phy_lock = 1000 * 1000 * tps4 / port_clock / 10; + int lttpr_count = 0; int tcds, establishment_period; - tcds = (7 + DIV_ROUND_UP(6500, tml_phy_lock) + 1) * tml_phy_lock; - establishment_period = (SILENCE_PERIOD_TIME + t1 + tcds); + if (intel_dp_is_edp(intel_dp)) { + tcds = (7 + DIV_ROUND_UP(6500, tml_phy_lock) + 1) * tml_phy_lock; + } else { + tcds = 7 * tml_phy_lock; + lttpr_count = drm_dp_lttpr_count(intel_dp->lttpr_common_caps); + } + + if (lttpr_count) { + int tlw = 13000; + int tcs = 10000; + int tlfps_period = get_lfps_cycle_time(crtc_state); + int tdcs = (SILENCE_PERIOD_TIME + t1 + tcs + + (lttpr_count - 1) * (tlw + tlfps_period)); + int tacds = 70000; + int tds = (lttpr_count - 1) * 7 * tml_phy_lock; + + /* tdrl is same as tcds*/ + establishment_period = tlw + tlfps_period + tdcs + tacds + tds + tcds; + } else { + /* TODO: Add a check for data realign by DPCD 0x116[3] */ + + establishment_period = (SILENCE_PERIOD_TIME + t1 + tcds); + } return establishment_period; } +static int get_switch_to_active(const struct intel_crtc_state *crtc_state) +{ + int port_clock = crtc_state->port_clock; + int switch_to_active; + + if (intel_dp_is_uhbr(crtc_state)) { + int symbol_clock = port_clock / intel_dp_link_symbol_size(port_clock); + + switch_to_active = 32 * DIV_ROUND_UP((396 + 3 + 64), symbol_clock); + } else { + switch_to_active = 0; + } + + return switch_to_active; +} + /* * AUX-Less Wake Time = CEILING( ((PHY P2 to P0) + tLFPS_Period, Max+ * tSilence, Max+ tPHY Establishment + tCDS) / tline)
@@ -129,9 +169,10 @@ static int _lnl_compute_aux_less_wake_time(struct intel_dp *intel_dp, { int tphy2_p2_to_p0 = get_tphy2_p2_to_p0(intel_dp); int establishment_period = get_establishment_period(intel_dp, crtc_state); + int switch_to_active = get_switch_to_active(crtc_state); return DIV_ROUND_UP(tphy2_p2_to_p0 + get_lfps_cycle_time(crtc_state) + - establishment_period, 1000); + establishment_period + switch_to_active, 1000); } static int
--
2.29.0