[Intel-gfx] [PATCH] drm/i915/dsi: Do not read the transcoder register.

[Vandita Kulkarni]

As per the Bspec, port mapping is fixed for mipi dsi.

v2: Reuse the existing function (Jani)

Signed-off-by: Vandita Kulkarni <vandita.kulkarni at intel.com>
---
 drivers/gpu/drm/i915/display/intel_display.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 23f00a651738..dccb94b24d14 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -10577,16 +10577,21 @@ static void haswell_get_ddi_port_state(struct intel_crtc *crtc,
 				       struct intel_crtc_state *pipe_config)
 {
 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
+	enum transcoder cpu_transcoder = pipe_config->cpu_transcoder;
 	struct intel_shared_dpll *pll;
 	enum port port;
 	u32 tmp;
 
-	tmp = I915_READ(TRANS_DDI_FUNC_CTL(pipe_config->cpu_transcoder));
-
-	if (INTEL_GEN(dev_priv) >= 12)
-		port = TGL_TRANS_DDI_FUNC_CTL_VAL_TO_PORT(tmp);
-	else
-		port = TRANS_DDI_FUNC_CTL_VAL_TO_PORT(tmp);
+	if (transcoder_is_dsi(cpu_transcoder)) {
+		port = (cpu_transcoder == TRANSCODER_DSI_A) ?
+						PORT_A : PORT_B;
+	} else {
+		tmp = I915_READ(TRANS_DDI_FUNC_CTL(cpu_transcoder));
+		if (INTEL_GEN(dev_priv) >= 12)
+			port = TGL_TRANS_DDI_FUNC_CTL_VAL_TO_PORT(tmp);
+		else
+			port = TRANS_DDI_FUNC_CTL_VAL_TO_PORT(tmp);
+	}
 
 	if (INTEL_GEN(dev_priv) >= 11)
 		icelake_get_ddi_pll(dev_priv, port, pipe_config);
-- 
2.21.0.5.gaeb582a