[Intel-gfx] [PATCH stable-5.10 2/2] drm/i915: Skip vswing programming for TBT

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

commit eaf5bfe37db871031232d2bf2535b6ca92afbad8 upstream.

In thunderbolt mode the PHY is owned by the thunderbolt controller.
We are not supposed to touch it. So skip the vswing programming
as well (we already skipped the other steps not applicable to TBT).

Touching this stuff could supposedly interfere with the PHY
programming done by the thunderbolt controller.

Cc: stable at vger.kernel.org
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210128155948.13678-1-ville.syrjala@linux.intel.com
Reviewed-by: Imre Deak <imre.deak at intel.com>
(cherry picked from commit f8c6b615b921d8a1bcd74870f9105e62b0bceff3)
Signed-off-by: Jani Nikula <jani.nikula at intel.com>
(cherry picked from commit eaf5bfe37db871031232d2bf2535b6ca92afbad8)
---
 drivers/gpu/drm/i915/display/intel_ddi.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index 51f4f4374dea..cdb19ec66890 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -2597,6 +2597,9 @@ static void icl_mg_phy_ddi_vswing_sequence(struct intel_encoder *encoder,
 	u32 n_entries, val;
 	int ln, rate = 0;
 
+	if (enc_to_dig_port(encoder)->tc_mode == TC_PORT_TBT_ALT)
+		return;
+
 	if (type != INTEL_OUTPUT_HDMI) {
 		struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
 
@@ -2741,6 +2744,9 @@ tgl_dkl_phy_ddi_vswing_sequence(struct intel_encoder *encoder, int link_clock,
 	u32 n_entries, val, ln, dpcnt_mask, dpcnt_val;
 	int rate = 0;
 
+	if (enc_to_dig_port(encoder)->tc_mode == TC_PORT_TBT_ALT)
+		return;
+
 	if (type != INTEL_OUTPUT_HDMI) {
 		struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
 
-- 
2.26.2