[PATCH 5.11 767/775] drm/i915: Reject 446-480MHz HDMI clock on GLK

From: Greg Kroah-Hartman
Date: Tue Mar 02 2021 - 01:41:42 EST


From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>

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@xxxxxxxxxxxxxxx
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/3000
Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20210203093044.30532-1-ville.syrjala@xxxxxxxxxxxxxxx
Reviewed-by: Mika Kahola <mika.kahola@xxxxxxxxx>
(cherry picked from commit 41751b3e5c1ac656a86f8d45a8891115281b729e)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/display/intel_hdmi.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/i915/display/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
@@ -2216,7 +2216,11 @@ hdmi_port_clock_valid(struct intel_hdmi
has_hdmi_sink))
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;