[PATCH v2 14/16] drm/i915/ddi: handle 128b/132b SST in intel_ddi_read_func_ctl()

[Jani Nikula]

We'll only ever get here in MST mode from MST stream encoders; the
primary encoder's ->get_config() won't be called when we've detected
it's MST.

v2: Read mst_master_transcoder in 128b/132b SST path (Imre)

Signed-off-by: Jani Nikula <jani.nik...@intel.com>
---
 drivers/gpu/drm/i915/display/intel_ddi.c | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c 
b/drivers/gpu/drm/i915/display/intel_ddi.c
index 04118f2eea94..37b771f07d59 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -4026,6 +4026,11 @@ static void intel_ddi_read_func_ctl_dp_sst(struct 
intel_encoder *encoder,
        crtc_state->lane_count =
                ((ddi_func_ctl & DDI_PORT_WIDTH_MASK) >> DDI_PORT_WIDTH_SHIFT) 
+ 1;
 
+       if (DISPLAY_VER(display) >= 12 &&
+           (ddi_func_ctl & TRANS_DDI_MODE_SELECT_MASK) == 
TRANS_DDI_MODE_SELECT_FDI_OR_128B132B)
+               crtc_state->mst_master_transcoder =
+                       REG_FIELD_GET(TRANS_DDI_MST_TRANSPORT_SELECT_MASK, 
ddi_func_ctl);
+
        intel_cpu_transcoder_get_m1_n1(crtc, cpu_transcoder, 
&crtc_state->dp_m_n);
        intel_cpu_transcoder_get_m2_n2(crtc, cpu_transcoder, 
&crtc_state->dp_m2_n2);
 
@@ -4120,9 +4125,19 @@ static void intel_ddi_read_func_ctl(struct intel_encoder 
*encoder,
                intel_ddi_read_func_ctl_fdi(encoder, pipe_config, ddi_func_ctl);
        } else if (ddi_mode == TRANS_DDI_MODE_SELECT_DP_SST) {
                intel_ddi_read_func_ctl_dp_sst(encoder, pipe_config, 
ddi_func_ctl);
-       } else if (ddi_mode == TRANS_DDI_MODE_SELECT_DP_MST ||
-                  (ddi_mode == TRANS_DDI_MODE_SELECT_FDI_OR_128B132B && 
HAS_DP20(display))) {
+       } else if (ddi_mode == TRANS_DDI_MODE_SELECT_DP_MST) {
                intel_ddi_read_func_ctl_dp_mst(encoder, pipe_config, 
ddi_func_ctl);
+       } else if (ddi_mode == TRANS_DDI_MODE_SELECT_FDI_OR_128B132B && 
HAS_DP20(display)) {
+               struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
+
+               /*
+                * If this is true, we know we're being called from mst stream
+                * encoder's ->get_config().
+                */
+               if (intel_dp->is_mst)
+                       intel_ddi_read_func_ctl_dp_mst(encoder, pipe_config, 
ddi_func_ctl);
+               else
+                       intel_ddi_read_func_ctl_dp_sst(encoder, pipe_config, 
ddi_func_ctl);
        }
 }
 
-- 
2.39.5