> -----Original Message----- > From: Intel-gfx <intel-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx> On Behalf Of Ville > Syrjala > Sent: Friday, March 11, 2022 11:29 PM > To: intel-gfx@xxxxxxxxxxxxxxxxxxxxx > Cc: stable@xxxxxxxxxxxxxxx > Subject: [PATCH] drm/i915: Reject unsupported TMDS rates on ICL+ > > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > 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@xxxxxxxxxxxxxxx > Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/5247 > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Reviewed-by: Mika Kahola <mika.kahola@xxxxxxxxx> > --- > 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. > -- > 2.34.1
