From: Jani Nikula <jani.nikula@intel.com>
Date: Mon, 5 Feb 2018 19:31:38 +0200
Subject: drm/i915: have virtual PCH detection return a PCH id
Git-commit: 40ace64b1ece1b8a29f86e6e2bc6fb91f7f0e537
Patch-mainline: v4.17-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

Simplify intel_virt_detect_pch() by making it return a PCH id rather
than returning the PCH type and setting PCH id for some PCHs. Map the
PCH id to PCH type using the shared routine. This gives us sanity check
on the supported combinations also in the virtualized setting.

Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/197cf635261a1c628371ffaaee90e8647493af4d.1517851783.git.jani.nikula@intel.com

Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/i915/i915_drv.c |   66 +++++++++++++++++++++-------------------
 1 file changed, 35 insertions(+), 31 deletions(-)

--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -202,9 +202,10 @@ static bool intel_is_virt_pch(unsigned s
 		 sdevice == PCI_SUBDEVICE_ID_QEMU));
 }
 
-static enum intel_pch intel_virt_detect_pch(struct drm_i915_private *dev_priv)
+static unsigned short
+intel_virt_detect_pch(const struct drm_i915_private *dev_priv)
 {
-	enum intel_pch ret = PCH_NOP;
+	unsigned short id = 0;
 
 	/*
 	 * In a virtualized passthrough environment we can be in a
@@ -213,28 +214,25 @@ static enum intel_pch intel_virt_detect_
 	 * make an educated guess as to which PCH is really there.
 	 */
 
-	if (IS_GEN5(dev_priv)) {
-		ret = PCH_IBX;
-		DRM_DEBUG_KMS("Assuming Ibex Peak PCH\n");
-	} else if (IS_GEN6(dev_priv) || IS_IVYBRIDGE(dev_priv)) {
-		ret = PCH_CPT;
-		DRM_DEBUG_KMS("Assuming CougarPoint PCH\n");
-	} else if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv)) {
-		ret = PCH_LPT;
-		if (IS_HSW_ULT(dev_priv) || IS_BDW_ULT(dev_priv))
-			dev_priv->pch_id = INTEL_PCH_LPT_LP_DEVICE_ID_TYPE;
-		else
-			dev_priv->pch_id = INTEL_PCH_LPT_DEVICE_ID_TYPE;
-		DRM_DEBUG_KMS("Assuming LynxPoint PCH\n");
-	} else if (IS_SKYLAKE(dev_priv) || IS_KABYLAKE(dev_priv)) {
-		ret = PCH_SPT;
-		DRM_DEBUG_KMS("Assuming SunrisePoint PCH\n");
-	} else if (IS_COFFEELAKE(dev_priv) || IS_CANNONLAKE(dev_priv)) {
-		ret = PCH_CNP;
-		DRM_DEBUG_KMS("Assuming CannonPoint PCH\n");
-	}
+	if (IS_GEN5(dev_priv))
+		id = INTEL_PCH_IBX_DEVICE_ID_TYPE;
+	else if (IS_GEN6(dev_priv) || IS_IVYBRIDGE(dev_priv))
+		id = INTEL_PCH_CPT_DEVICE_ID_TYPE;
+	else if (IS_HSW_ULT(dev_priv) || IS_BDW_ULT(dev_priv))
+		id = INTEL_PCH_LPT_LP_DEVICE_ID_TYPE;
+	else if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv))
+		id = INTEL_PCH_LPT_DEVICE_ID_TYPE;
+	else if (IS_SKYLAKE(dev_priv) || IS_KABYLAKE(dev_priv))
+		id = INTEL_PCH_SPT_DEVICE_ID_TYPE;
+	else if (IS_COFFEELAKE(dev_priv) || IS_CANNONLAKE(dev_priv))
+		id = INTEL_PCH_CNP_DEVICE_ID_TYPE;
+
+	if (id)
+		DRM_DEBUG_KMS("Assuming PCH ID %04x\n", id);
+	else
+		DRM_DEBUG_KMS("Assuming no PCH\n");
 
-	return ret;
+	return id;
 }
 
 static void intel_detect_pch(struct drm_i915_private *dev_priv)
@@ -269,19 +267,25 @@ static void intel_detect_pch(struct drm_
 
 		id = pch->device & INTEL_PCH_DEVICE_ID_MASK;
 
-		dev_priv->pch_id = id;
-
 		pch_type = intel_pch_type(dev_priv, id);
 		if (pch_type != PCH_NONE) {
 			dev_priv->pch_type = pch_type;
+			dev_priv->pch_id = id;
+			break;
 		} else if (intel_is_virt_pch(id, pch->subsystem_vendor,
-					     pch->subsystem_device)) {
-			dev_priv->pch_type = intel_virt_detect_pch(dev_priv);
-		} else {
-			continue;
+					 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_NOP;
+			}
+			dev_priv->pch_type = pch_type;
+			dev_priv->pch_id = id;
+			break;
 		}
-
-		break;
 	}
 	if (!pch)
 		DRM_DEBUG_KMS("No PCH found.\n");