Handle monitors in different GPU's

sunshine/platform/linux/kmsgrab.cpp

@@ -5,6 +5,8 @@
 #include <xf86drm.h>
 #include <xf86drmMode.h>
 
+#include <filesystem>
+
 #include "sunshine/main.h"
 #include "sunshine/platform/common.h"
 #include "sunshine/round_robin.h"
@@ -14,6 +16,7 @@
 #include "vaapi.h"
 
 using namespace std::literals;
+namespace fs = std::filesystem;
 
 namespace platf {
 
@@ -235,14 +238,23 @@ public:
   int init(const std::string &display_name, int framerate) {
     delay = std::chrono::nanoseconds { 1s } / framerate;
 
-    constexpr auto path = "/dev/dri/card1";
-    if(card.init(path)) {
-      return -1;
-    }
-
     int monitor_index = util::from_view(display_name);
     int monitor       = 0;
 
+    fs::path card_dir { "/dev/dri"sv };
+    for(auto &entry : fs::directory_iterator { card_dir }) {
+      auto file = entry.path().filename();
+
+      auto filestring = file.generic_u8string();
+      if(std::string_view { filestring }.substr(0, 4) != "card"sv) {
+        continue;
+      }
+
+      kms::card_t card;
+      if(card.init(entry.path().c_str())) {
+        return {};
+      }
+
       auto end = std::end(card);
       for(auto plane = std::begin(card); plane != end; ++plane) {
         if(monitor != monitor_index) {
@@ -287,9 +299,13 @@ public:
         offset_x = crct->x;
         offset_y = crct->y;
 
-      break;
+        this->card = std::move(card);
+        goto break_loop;
+      }
     }
 
+  // Neatly break from nested for loop
+  break_loop:
     if(monitor != monitor_index) {
       BOOST_LOG(error) << "Couldn't find monitor ["sv << monitor_index << ']';
 
@@ -525,6 +541,11 @@ std::shared_ptr<display_t> kms_display(mem_type_e hwdevice_type, const std::stri
 
 // A list of names of displays accepted as display_name
 std::vector<std::string> kms_display_names() {
+  kms::env_width  = 0;
+  kms::env_height = 0;
+
+  int count = 0;
+
   if(!gbm::create_device) {
     BOOST_LOG(warning) << "libgbm not initialized"sv;
     return {};
@@ -532,15 +553,19 @@ std::vector<std::string> kms_display_names() {
 
   std::vector<std::string> display_names;
 
-  kms::card_t card;
-  if(card.init("/dev/dri/card1")) {
-    return {};
+  fs::path card_dir { "/dev/dri"sv };
+  for(auto &entry : fs::directory_iterator { card_dir }) {
+    auto file = entry.path().filename();
+
+    auto filestring = file.generic_u8string();
+    if(std::string_view { filestring }.substr(0, 4) != "card"sv) {
+      continue;
     }
 
-  kms::env_width  = 0;
-  kms::env_height = 0;
-
-  int count = 0;
+    kms::card_t card;
+    if(card.init(entry.path().c_str())) {
+      return {};
+    }
 
     auto end = std::end(card);
     for(auto plane = std::begin(card); plane != end; ++plane) {
@@ -597,6 +622,7 @@ std::vector<std::string> kms_display_names() {
 
       display_names.emplace_back(std::to_string(count++));
     }
+  }
 
   return display_names;
 }