From fa4aa0b271db78de3d1bace6e3383cd65efa31b1 Mon Sep 17 00:00:00 2001 From: Suraj Kandpal Date: Mon, 10 Nov 2025 11:49:41 +0530 Subject: [PATCH] drm/i915/ltphy: Return lowest portclock for HDMI from reverse algorithm Return the lowest port clock for HDMI when the reverse algorithm calculates it to be 0 to avoid errors later but throw a warn. Signed-off-by: Suraj Kandpal Reviewed-by: Ankit Nautiyal Link: https://patch.msgid.link/20251110061940.545183-2-suraj.kandpal@intel.com --- drivers/gpu/drm/i915/display/intel_lt_phy.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_lt_phy.c b/drivers/gpu/drm/i915/display/intel_lt_phy.c index 1f6b240c8aaff..b2413b385dc81 100644 --- a/drivers/gpu/drm/i915/display/intel_lt_phy.c +++ b/drivers/gpu/drm/i915/display/intel_lt_phy.c @@ -1680,7 +1680,7 @@ intel_lt_phy_calculate_hdmi_state(struct intel_lt_phy_pll_state *lt_state, } static int -intel_lt_phy_calc_hdmi_port_clock(const struct intel_lt_phy_pll_state *lt_state) +intel_lt_phy_calc_hdmi_port_clock(const struct intel_crtc_state *crtc_state) { #define REGVAL(i) ( \ (lt_state->data[i][3]) | \ @@ -1689,6 +1689,9 @@ intel_lt_phy_calc_hdmi_port_clock(const struct intel_lt_phy_pll_state *lt_state) (lt_state->data[i][0] << 24) \ ) + struct intel_display *display = to_intel_display(crtc_state); + const struct intel_lt_phy_pll_state *lt_state = + &crtc_state->dpll_hw_state.ltpll; int clk = 0; u32 d8, pll_reg_5, pll_reg_3, pll_reg_57, m2div_frac, m2div_int; u64 temp0, temp1; @@ -1731,11 +1734,14 @@ intel_lt_phy_calc_hdmi_port_clock(const struct intel_lt_phy_pll_state *lt_state) * frequency = (m2div * refclk_khz / (d8 * 10)) */ d8 = (pll_reg_57 & REG_GENMASK(14, 7)) >> 7; + if (d8 == 0) { + drm_WARN_ON(display->drm, + "Invalid port clock using lowest HDMI portclock\n"); + return xe3plpd_lt_hdmi_252.clock; + } m2div_int = (pll_reg_3 & REG_GENMASK(14, 5)) >> 5; temp0 = ((u64)m2div_frac * REF_CLK_KHZ) >> 32; temp1 = (u64)m2div_int * REF_CLK_KHZ; - if (d8 == 0) - return 0; clk = div_u64((temp1 + temp0), d8 * 10); @@ -1764,7 +1770,7 @@ intel_lt_phy_calc_port_clock(struct intel_encoder *encoder, lt_state->config[0]); clk = intel_lt_phy_get_dp_clock(rate); } else { - clk = intel_lt_phy_calc_hdmi_port_clock(lt_state); + clk = intel_lt_phy_calc_hdmi_port_clock(crtc_state); } return clk; -- 2.47.3