From 8423f848d0d8c4846fcc2eac186131ef44e6d249 Mon Sep 17 00:00:00 2001
From: Techjar <tecknojar@gmail.com>
Date: Mon, 1 Jun 2020 16:59:45 -0400
Subject: [PATCH] ControllerInterface: Combine evdev devices with the same
 physical location in addition to unique ID

---
 .../ControllerInterface/evdev/evdev.cpp       | 25 +++++++++++++++----
 .../ControllerInterface/evdev/evdev.h         |  1 +
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/Source/Core/InputCommon/ControllerInterface/evdev/evdev.cpp b/Source/Core/InputCommon/ControllerInterface/evdev/evdev.cpp
index c825da6b7b..77f796b22f 100644
--- a/Source/Core/InputCommon/ControllerInterface/evdev/evdev.cpp
+++ b/Source/Core/InputCommon/ControllerInterface/evdev/evdev.cpp
@@ -204,9 +204,10 @@ static int s_wakeup_eventfd;
 // sysfs is not stable, so this is probably the easiest way to get a name for a node.
 static std::map<std::string, std::weak_ptr<evdevDevice>> s_devnode_objects;
 
-static std::shared_ptr<evdevDevice> FindDeviceWithUniqueID(const char* unique_id)
+static std::shared_ptr<evdevDevice>
+FindDeviceWithUniqueIDAndPhysicalLocation(const char* unique_id, const char* physical_location)
 {
-  if (!unique_id)
+  if (!unique_id || !physical_location)
     return nullptr;
 
   for (auto& [node, dev] : s_devnode_objects)
@@ -214,9 +215,13 @@ static std::shared_ptr<evdevDevice> FindDeviceWithUniqueID(const char* unique_id
     if (const auto device = dev.lock())
     {
       const auto* dev_uniq = device->GetUniqueID();
+      const auto* dev_phys = device->GetPhysicalLocation();
 
-      if (dev_uniq && std::strcmp(dev_uniq, unique_id) == 0)
+      if (dev_uniq && dev_phys && std::strcmp(dev_uniq, unique_id) == 0 &&
+          std::strcmp(dev_phys, physical_location) == 0)
+      {
         return device;
+      }
     }
   }
 
@@ -244,10 +249,12 @@ static void AddDeviceNode(const char* devnode)
   }
 
   const auto uniq = libevdev_get_uniq(dev);
-  auto evdev_device = FindDeviceWithUniqueID(uniq);
+  const auto phys = libevdev_get_phys(dev);
+  auto evdev_device = FindDeviceWithUniqueIDAndPhysicalLocation(uniq, phys);
   if (evdev_device)
   {
-    NOTICE_LOG(SERIALINTERFACE, "evdev combining devices with unique id: %s", uniq);
+    NOTICE_LOG(SERIALINTERFACE, "evdev combining devices with unique id: %s, physical location: %s",
+               uniq, phys);
 
     evdev_device->AddNode(devnode, fd, dev);
 
@@ -589,6 +596,14 @@ const char* evdevDevice::GetUniqueID() const
   return uniq;
 }
 
+const char* evdevDevice::GetPhysicalLocation() const
+{
+  if (m_nodes.empty())
+    return nullptr;
+
+  return libevdev_get_phys(m_nodes.front().device);
+}
+
 evdevDevice::~evdevDevice()
 {
   for (auto& node : m_nodes)
diff --git a/Source/Core/InputCommon/ControllerInterface/evdev/evdev.h b/Source/Core/InputCommon/ControllerInterface/evdev/evdev.h
index 3c60e2cb57..f37c7c78d0 100644
--- a/Source/Core/InputCommon/ControllerInterface/evdev/evdev.h
+++ b/Source/Core/InputCommon/ControllerInterface/evdev/evdev.h
@@ -82,6 +82,7 @@ public:
   bool AddNode(std::string devnode, int fd, libevdev* dev);
 
   const char* GetUniqueID() const;
+  const char* GetPhysicalLocation() const;
 
   std::string GetName() const override { return m_name; }
   std::string GetSource() const override { return "evdev"; }