[PATCH 5.5 117/150] drm/i915/ehl: Update port clock voltage level requirements

[Greg Kroah-Hartman]

From: Matt Roper <matthew.d.roper@xxxxxxxxx>

commit 58e9121c32a245fab47f29ab4ad29dd62470a7e8 upstream.

Voltage level depends not only on the cdclk, but also on the DDI clock.
Last time the bspec voltage level table for EHL was updated, we only
updated the cdclk requirements, but forgot to account for the new port
clock criteria.

Bspec: 21809
Fixes: d147483884ed ("drm/i915/ehl: Update voltage level checks")
Cc: Josà Roberto de Souza <jose.souza@xxxxxxxxx>
Signed-off-by: Matt Roper <matthew.d.roper@xxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20200207001417.1229251-1-matthew.d.roper@xxxxxxxxx
Reviewed-by: Josà Roberto de Souza <jose.souza@xxxxxxxxx>
(cherry picked from commit 9d5fd37ed7e26efdbe90f492d7eb8b53dcdb61d6)
Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/gpu/drm/i915/display/intel_ddi.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -4227,7 +4227,9 @@ static bool intel_ddi_is_audio_enabled(s
 void intel_ddi_compute_min_voltage_level(struct drm_i915_private *dev_priv,
 					 struct intel_crtc_state *crtc_state)
 {
-	if (INTEL_GEN(dev_priv) >= 11 && crtc_state->port_clock > 594000)
+	if (IS_ELKHARTLAKE(dev_priv) && crtc_state->port_clock > 594000)
+		crtc_state->min_voltage_level = 3;
+	else if (INTEL_GEN(dev_priv) >= 11 && crtc_state->port_clock > 594000)
 		crtc_state->min_voltage_level = 1;
 	else if (IS_CANNONLAKE(dev_priv) && crtc_state->port_clock > 594000)
 		crtc_state->min_voltage_level = 2;