From: Jani Nikula <jani.nikula@intel.com>
Date: Fri, 8 Jun 2018 15:33:28 +0300
Subject: drm/i915: clean up virtual PCH special case handling
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Git-commit: 85b17e6e4d3f288cc757ff5407b2ca6604673d74
Patch-mainline: v4.19-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

Use intel_pch_type() also for mapping the no PCH case (PCH id 0) to
PCH_NONE to simplify code.

Also make sure that intel_pch_type() knows all the PCH ids returned by
intel_virt_detect_pch(). Loudly fail if this isn't the case; this
shouldn't happen anyway.

Cc: Colin Xu <Colin.Xu@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: Colin Xu <Colin.Xu@intel.com>
Reviewed-by: Colin Xu <Colin.Xu@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180608123330.31003-4-jani.nikula@intel.com

Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/i915/i915_drv.c |   13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -284,13 +284,12 @@ static void intel_detect_pch(struct drm_
 		} else if (intel_is_virt_pch(id, pch->subsystem_vendor,
 					 pch->subsystem_device)) {
 			id = intel_virt_detect_pch(dev_priv);
-			if (id) {
-				pch_type = intel_pch_type(dev_priv, id);
-				if (WARN_ON(pch_type == PCH_NONE))
-					pch_type = PCH_NOP;
-			} else {
-				pch_type = PCH_NONE;
-			}
+			pch_type = intel_pch_type(dev_priv, id);
+
+			/* Sanity check virtual PCH id */
+			if (WARN_ON(id && pch_type == PCH_NONE))
+				id = 0;
+
 			dev_priv->pch_type = pch_type;
 			dev_priv->pch_id = id;
 			break;