From 9cddf03b2af07443bebdc73cba21acb360c079e8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@linux.intel.com>
Date: Fri, 11 Mar 2022 23:28:45 +0200
Subject: [PATCH] drm/i915: Reject unsupported TMDS rates on ICL+
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Git-commit: 9cddf03b2af07443bebdc73cba21acb360c079e8
Patch-mainline: v5.18-rc1
Alt-commit: e5086cb3f3d3f94091be29eec38cf13f8a75a778
References: git-fixes

ICL+ PLLs can't genenerate certain frequencies. Running the PLL
algorithms through for all frequencies 25-594MHz we see a gap just
above 500 MHz. Specifically 500-522.8MHZ for TC PLLs, and 500-533.2
MHz for combo PHY PLLs. Reject those frequencies hdmi_port_clock_valid()
so that we properly filter out unsupported modes and/or color depths
for HDMI.

Cc: stable@vger.kernel.org
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/5247
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220311212845.32358-1-ville.syrjala@linux.intel.com
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
(cherry picked from commit e5086cb3f3d3f94091be29eec38cf13f8a75a778)

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/i915/display/intel_hdmi.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c
index 1aa5bdc7b0dc..6512f014cad4 100644
--- a/drivers/gpu/drm/i915/display/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
@@ -1836,6 +1836,7 @@ hdmi_port_clock_valid(struct intel_hdmi *hdmi,
 		      bool has_hdmi_sink)
 {
 	struct drm_i915_private *dev_priv = intel_hdmi_to_i915(hdmi);
+	enum phy phy = intel_port_to_phy(dev_priv, hdmi_to_dig_port(hdmi)->base.port);
 
 	if (clock < 25000)
 		return MODE_CLOCK_LOW;
@@ -1856,6 +1857,14 @@ hdmi_port_clock_valid(struct intel_hdmi *hdmi,
 	if (IS_CHERRYVIEW(dev_priv) && clock > 216000 && clock < 240000)
 		return MODE_CLOCK_RANGE;
 
+	/* ICL+ combo PHY PLL can't generate 500-533.2 MHz */
+	if (intel_phy_is_combo(dev_priv, phy) && clock > 500000 && clock < 533200)
+		return MODE_CLOCK_RANGE;
+
+	/* ICL+ TC PHY PLL can't generate 500-532.8 MHz */
+	if (intel_phy_is_tc(dev_priv, phy) && clock > 500000 && clock < 532800)
+		return MODE_CLOCK_RANGE;
+
 	/*
 	 * SNPS PHYs' MPLLB table-based programming can only handle a fixed
 	 * set of link rates.
-- 
2.35.3