From: Ville Syrjälä ville.syrjala@linux.intel.com
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 --- 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 f3e688f739f3..a4a6f8bd2841 100644 --- a/drivers/gpu/drm/i915/display/intel_hdmi.c +++ b/drivers/gpu/drm/i915/display/intel_hdmi.c @@ -1837,6 +1837,7 @@ 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; @@ -1857,6 +1858,14 @@ 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.