drm/i915: Reject 446-480MHz HDMI clock on GLK

commit 7a6c6243b44a439bda4bf099032be35ebcf53406 upstream.

The BXT/GLK DPLL can't generate certain frequencies. We already
reject the 233-240MHz range on both. But on GLK the DPLL max
frequency was bumped from 300MHz to 594MHz, so now we get to
also worry about the 446-480MHz range (double the original
problem range). Reject any frequency within the higher
problematic range as well.

Cc: stable@vger.kernel.org
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/3000
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210203093044.30532-1-ville.syrjala@linux.intel.com
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
(cherry picked from commit 41751b3e5c1ac656a86f8d45a8891115281b729e)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c
index b030f7ae330290393f3fe7136ccc078503b33828..4cf95e8031e38db015912689180d8aae32ecd991 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
@@ -2129,7 +2129,11 @@ hdmi_port_clock_valid(struct intel_hdmi *hdmi,
        if (clock > hdmi_port_clock_limit(hdmi, respect_downstream_limits, force_dvi))
                return MODE_CLOCK_HIGH;
 
-       /* BXT DPLL can't generate 223-240 MHz */
+       /* GLK DPLL can't generate 446-480 MHz */
+       if (IS_GEMINILAKE(dev_priv) && clock > 446666 && clock < 480000)
+               return MODE_CLOCK_RANGE;
+
+       /* BXT/GLK DPLL can't generate 223-240 MHz */
        if (IS_GEN9_LP(dev_priv) && clock > 223333 && clock < 240000)
                return MODE_CLOCK_RANGE;