From d5929835080a60f9119d024fa42f315913942f76 Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Mon, 13 Jun 2022 12:22:41 +0200 Subject: [PATCH] drm/i915/display: Re-add check for low voltage sku for max dp source rate This reverts commit 73867c8709b5 ("drm/i915/display: Remove check for low voltage sku for max dp source rate"), which, on an i7-11850H iGPU with a Thinkpad X1 Extreme Gen 4, attached to a LG LP160UQ1-SPB1 embedded panel, causes wild flickering glitching technicolor pyrotechnics on resumption from suspend. The display shows strobing colors in an utter disaster explosion of pantone, as though bombs were dropped on the leprechauns at the base of the rainbow. Rebooting the machine fixes the issue, presumably because the display is initialized by firmware rather than by i915. Otherwise, the GPU appears to work fine. Bisection traced it back to this commit, which makes sense given the issues. Note: This re-opens, and puts back to the drawing board, https://gitlab.freedesktop.org/drm/intel/-/issues/5272 which was fixed by the regressing commit. Fixes: 73867c8709b5 ("drm/i915/display: Remove check for low voltage sku for max dp source rate") Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/6205 Cc: Ankit Nautiyal Cc: Imre Deak Cc: Jani Nikula Cc: Uma Shankar Cc: Animesh Manna Cc: Jani Saarinen Signed-off-by: Jason A. Donenfeld Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/20220613102241.9236-1-Jason@zx2c4.com --- drivers/gpu/drm/i915/display/intel_dp.c | 32 ++++++++++++++++++++++--- 1 file changed, 29 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 368bd4cdf2ee..94ffbd7d807a 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -387,13 +387,23 @@ static int dg2_max_source_rate(struct intel_dp *intel_dp) return intel_dp_is_edp(intel_dp) ? 810000 : 1350000; } +static bool is_low_voltage_sku(struct drm_i915_private *i915, enum phy phy) +{ + u32 voltage; + + voltage = intel_de_read(i915, ICL_PORT_COMP_DW3(phy)) & VOLTAGE_INFO_MASK; + + return voltage == VOLTAGE_INFO_0_85V; +} + static int icl_max_source_rate(struct intel_dp *intel_dp) { struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp); struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev); enum phy phy = intel_port_to_phy(dev_priv, dig_port->base.port); - if (intel_phy_is_combo(dev_priv, phy) && !intel_dp_is_edp(intel_dp)) + if (intel_phy_is_combo(dev_priv, phy) && + (is_low_voltage_sku(dev_priv, phy) || !intel_dp_is_edp(intel_dp))) return 540000; return 810000; @@ -401,7 +411,23 @@ static int icl_max_source_rate(struct intel_dp *intel_dp) static int ehl_max_source_rate(struct intel_dp *intel_dp) { - if (intel_dp_is_edp(intel_dp)) + struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp); + struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev); + enum phy phy = intel_port_to_phy(dev_priv, dig_port->base.port); + + if (intel_dp_is_edp(intel_dp) || is_low_voltage_sku(dev_priv, phy)) + return 540000; + + return 810000; +} + +static int dg1_max_source_rate(struct intel_dp *intel_dp) +{ + struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp); + struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev); + enum phy phy = intel_port_to_phy(i915, dig_port->base.port); + + if (intel_phy_is_combo(i915, phy) && is_low_voltage_sku(i915, phy)) return 540000; return 810000; @@ -463,7 +489,7 @@ intel_dp_set_source_rates(struct intel_dp *intel_dp) max_rate = dg2_max_source_rate(intel_dp); else if (IS_ALDERLAKE_P(dev_priv) || IS_ALDERLAKE_S(dev_priv) || IS_DG1(dev_priv) || IS_ROCKETLAKE(dev_priv)) - max_rate = 810000; + max_rate = dg1_max_source_rate(intel_dp); else if (IS_JSL_EHL(dev_priv)) max_rate = ehl_max_source_rate(intel_dp); else -- 2.25.1