drm/i915: Skip vswing programming for TBT

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@vger.kernel.org
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210128155948.13678-1-ville.syrjala@linux.intel.com
Reviewed-by: Imre Deak <imre.deak@intel.com>

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index fbd857f2bdb2633c5f4c982df95e3a89ca7a8b75..2ac92e7f53355cdd9bd4e549ff8ba91c43ca2590 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -2827,6 +2827,9 @@ static void icl_mg_phy_ddi_vswing_sequence(struct intel_encoder *encoder,
        int n_entries, ln;
        u32 val;
 
+       if (enc_to_dig_port(encoder)->tc_mode == TC_PORT_TBT_ALT)
+               return;
+
        ddi_translations = icl_get_mg_buf_trans(encoder, crtc_state, &n_entries);
 
        if (drm_WARN_ON_ONCE(&dev_priv->drm, !ddi_translations))
@@ -2962,6 +2965,9 @@ tgl_dkl_phy_ddi_vswing_sequence(struct intel_encoder *encoder,
        u32 val, dpcnt_mask, dpcnt_val;
        int n_entries, ln;
 
+       if (enc_to_dig_port(encoder)->tc_mode == TC_PORT_TBT_ALT)
+               return;
+
        ddi_translations = tgl_get_dkl_buf_trans(encoder, crtc_state, &n_entries);
 
        if (drm_WARN_ON_ONCE(&dev_priv->drm, !ddi_translations))