[Intel-gfx] [PATCH] drm/i915/dp: Do not switch aux to TBT mode for non-TC ports

[José Roberto de Souza]

Non-TC ports always have tc_mode == TC_PORT_TBT_ALT so it was
switching aux to TC mode for all combo-phy ports, happily this did
not caused any issue but is better follow BSpec.
Also this is reserved bit before ICL.

Fixes: 6f211ed43438 ("drm/i915/icl: Set TBT IO in Aux transaction")
Cc: Imre Deak <imre.deak at intel.com>
Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
---
 drivers/gpu/drm/i915/display/intel_dp.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 86989ec25bc6..379623397301 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -1291,6 +1291,9 @@ static u32 skl_get_aux_send_ctl(struct intel_dp *intel_dp,
 				u32 unused)
 {
 	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
+	struct drm_i915_private *i915 =
+			to_i915(intel_dig_port->base.base.dev);
+	enum phy phy = intel_port_to_phy(i915, intel_dig_port->base.port);
 	u32 ret;
 
 	ret = DP_AUX_CH_CTL_SEND_BUSY |
@@ -1303,7 +1306,8 @@ static u32 skl_get_aux_send_ctl(struct intel_dp *intel_dp,
 	      DP_AUX_CH_CTL_FW_SYNC_PULSE_SKL(32) |
 	      DP_AUX_CH_CTL_SYNC_PULSE_SKL(32);
 
-	if (intel_dig_port->tc_mode == TC_PORT_TBT_ALT)
+	if (intel_phy_is_tc(i915, phy) &&
+	    intel_dig_port->tc_mode == TC_PORT_TBT_ALT)
 		ret |= DP_AUX_CH_CTL_TBT_IO;
 
 	return ret;
-- 
2.23.0