drm/i915/icl: Fix port disable sequence for mipi-dsi

Re-enable clock gating of DDI clocks.

v2: Fix the default ddi clk state for mipi-dsi (Imre)

Fixes: 1026bea0 ("drm/i915/icl: Ungate DSI clocks")
Signed-off-by: Vandita Kulkarni <vandita.kulkarni@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1553513202-13863-2-git-send-email-vandita.kulkarni@intel.com

drivers/gpu/drm/i915/icl_dsi.c

@@ -1138,7 +1138,7 @@ static void gen11_dsi_disable_port(struct intel_encoder *encoder)
 			DRM_ERROR("DDI port:%c buffer not idle\n",
 				  port_name(port));
 	}
-	gen11_dsi_ungate_clocks(encoder);
+	gen11_dsi_gate_clocks(encoder);
 }
 
 static void gen11_dsi_disable_io_power(struct intel_encoder *encoder)

drivers/gpu/drm/i915/intel_ddi.c

@@ -2802,10 +2802,10 @@ void icl_sanitize_encoder_pll_mapping(struct intel_encoder *encoder)
 				return;
 		}
 		/*
-		 * DSI ports should have their DDI clock ungated when disabled
-		 * and gated when enabled.
+		 * For DSI we keep the ddi clocks gated
+		 * except during enable/disable sequence.
 		 */
-		ddi_clk_needed = !encoder->base.crtc;
+		ddi_clk_needed = false;
 	}
 
 	val = I915_READ(DPCLKA_CFGCR0_ICL);