From 1d79c50e2eeae42b8aad7b5d4d0fe57027174e8a Mon Sep 17 00:00:00 2001 From: Suraj Kandpal Date: Tue, 11 Aug 2026 23:28:44 +0530 Subject: [PATCH] drm/i915/lt_phy: program DDI_CLK_VALFREQ with DDI clock frequency DDI_CLK_VALFREQ is programmed with the port clock, which for DP is the symbol clock computed assuming 8b/10b encoding (link_rate / 10). For DP 128b/132b (UHBR) rates and for HDMI FRL the port clock needs to be modified. DDI_CLK_VALFREQ does not have any functional impact on H/w, it only records the frequency S/w intends to set. Use intel_ddi_link_symbol_clock() to write the correct DDI clock in kHz Fixes: 5ec58d714935 ("drm/i915/lt_phy: Add .enable_clock hook on DDI") Signed-off-by: Suraj Kandpal Reviewed-by: Ankit Nautiyal Link: https://patch.msgid.link/20260811175844.2613721-4-suraj.kandpal@intel.com (cherry picked from commit eaed815ca3483c227e4ec80b86d1b3ce5c2508be) Signed-off-by: Jani Nikula --- drivers/gpu/drm/i915/display/intel_lt_phy.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_lt_phy.c b/drivers/gpu/drm/i915/display/intel_lt_phy.c index 8fc6d230493f..86492651b01d 100644 --- a/drivers/gpu/drm/i915/display/intel_lt_phy.c +++ b/drivers/gpu/drm/i915/display/intel_lt_phy.c @@ -1976,7 +1976,8 @@ void intel_lt_phy_pll_enable(struct intel_encoder *encoder, * Change. We handle this step in bxt_set_cdclk(). */ /* 10. Program DDI_CLK_VALFREQ to match intended DDI clock frequency. */ - intel_de_write(display, DDI_CLK_VALFREQ(encoder->port), port_clock); + intel_de_write(display, DDI_CLK_VALFREQ(encoder->port), + intel_ddi_link_symbol_clock(encoder, port_clock)); /* 11. Program PORT_CLOCK_CTL[PCLK PLL Request LN0] = 1. */ intel_de_rmw(display, XELPDP_PORT_CLOCK_CTL(display, port), @@ -2023,7 +2024,8 @@ void intel_lt_phy_pll_enable(struct intel_encoder *encoder, lane_phy_pulse_status, lane_phy_pulse_status); } else { - intel_de_write(display, DDI_CLK_VALFREQ(encoder->port), port_clock); + intel_de_write(display, DDI_CLK_VALFREQ(encoder->port), + intel_ddi_link_symbol_clock(encoder, port_clock)); } /*