added linux feature flag to enable 5ghz hotspot

internal/platform/implementation/linux/BUILD

@@ -14,8 +14,6 @@
 
 #load("@hedron_compile_commands//:refresh_compile_commands.bzl", "refresh_compile_commands")
 
-licenses(["notice"])
-
 load("@rules_cc//cc:defs.bzl", "cc_library", "cc_test")
 #refresh_compile_commands(
 #    name = "refresh_compile_commands",
@@ -34,12 +32,15 @@ load("@rules_cc//cc:defs.bzl", "cc_library", "cc_test")
 #    # And if you're working on a header-only library, specify a test or binary target that compiles it.
 #)
 
+licenses(["notice"])
+
 cc_library(
     name = "types",
     srcs = [
         "device_info.cc",
         #"log_message.cc",
         "timer.cc",
+        "linux_flags.cc",
     ],
     hdrs = [
         "atomic_boolean.h",
@@ -57,6 +58,7 @@ cc_library(
         "submittable_executor.h",
         "timer.h",
         "thread_pool.h",
+        "linux_flags.h",
         #"log_message.h",
         "utils.h",
     ],
@@ -152,10 +154,10 @@ cc_library(
     srcs = [
         "crypto.cc",
     ],
-    visibility = ["//visibility:public"],
-    linkopts= [
+    linkopts = [
         "-lcrypto",
     ],
+    visibility = ["//visibility:public"],
     deps = [
         "//internal/platform:base",
         "//internal/platform/implementation:types",
@@ -168,7 +170,6 @@ cc_library(
     srcs = [
         "system_clock.cc",
     ],
-    alwayslink = True,
     visibility = [
         "//sharing/linux:__pkg__",
     ],
@@ -177,6 +178,7 @@ cc_library(
         "//internal/platform/implementation:types",
         "@com_google_absl//absl/time",
     ],
+    alwayslink = True,
 )
 
 cc_library(
@@ -242,6 +244,7 @@ cc_library(
         ":crypto",  # build_cleaner: keep
         ":system_clock",
         ":types",
+        "//connections/implementation/flags:connections_flags",
         "//internal/flags:nearby_flags",
         "//internal/platform:base",
         "//internal/platform:cancellation_flag",
@@ -256,7 +259,6 @@ cc_library(
         "//internal/platform/implementation/shared:count_down_latch",
         "//internal/platform/implementation/shared:file",
         "//proto/mediums:ble_frames_cc_proto",
-        "//connections/implementation/flags:connections_flags",
         "@com_google_absl//absl/base:core_headers",
         "@com_google_absl//absl/container:flat_hash_map",
         "@com_google_absl//absl/functional:any_invocable",

internal/platform/implementation/linux/linux_flags.cc

@@ -0,0 +1,30 @@
+// Copyright 2026 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "internal/platform/implementation/linux/linux_flags.h"
+
+#include <atomic>
+
+namespace nearby::linux {
+namespace {
+
+std::atomic_bool kEnable5GhzHotspot = true;
+
+}  // namespace
+
+bool Is5GhzHotspotEnabled() { return kEnable5GhzHotspot.load(); }
+
+void Set5GhzHotspotEnabled(bool enabled) { kEnable5GhzHotspot.store(enabled); }
+
+}  // namespace nearby::linux

internal/platform/implementation/linux/linux_flags.h

@@ -0,0 +1,25 @@
+// Copyright 2026 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef PLATFORM_IMPL_LINUX_LINUX_FLAGS_H_
+#define PLATFORM_IMPL_LINUX_LINUX_FLAGS_H_
+
+namespace nearby::linux {
+
+bool Is5GhzHotspotEnabled();
+void Set5GhzHotspotEnabled(bool enabled);
+
+}  // namespace nearby::linux
+
+#endif  // PLATFORM_IMPL_LINUX_LINUX_FLAGS_H_

internal/platform/implementation/linux/wifi_hotspot.cc

@@ -21,6 +21,7 @@
 #include <random>
 
 #include "internal/platform/implementation/linux/dbus.h"
+#include "internal/platform/implementation/linux/linux_flags.h"
 #include "internal/platform/implementation/linux/network_manager.h"
 #include "internal/platform/implementation/linux/network_manager_access_point.h"
 #include "internal/platform/implementation/linux/utils.h"
@@ -164,7 +165,9 @@ bool NetworkManagerWifiHotspotMedium::StartWifiHotspot(
   api::WifiCapability& capability = wireless_device_->GetCapability();
   std::string selected_band;
   int selected_channel = kPreferred24GhzChannel;
-  if (capability.supports_6_ghz || capability.supports_5_ghz) {
+  const bool enable_5ghz_hotspot = Is5GhzHotspotEnabled();
+  if (enable_5ghz_hotspot &&
+      (capability.supports_6_ghz || capability.supports_5_ghz)) {
     selected_band = "a";  // 5/6 GHz - NetworkManager uses "a" for both 5 GHz and 6 GHz
     selected_channel = kPreferred5GhzChannel;
     LOG(INFO) << __func__
@@ -173,9 +176,16 @@ bool NetworkManagerWifiHotspotMedium::StartWifiHotspot(
   } else {
     selected_band = "bg";  // 2.4 GHz
     selected_channel = kPreferred24GhzChannel;
-    LOG(INFO) << __func__
-              << ": Device supports only 2.4 GHz, using 2.4 GHz band on "
-              << "channel " << selected_channel;
+    if (!enable_5ghz_hotspot &&
+        (capability.supports_6_ghz || capability.supports_5_ghz)) {
+      LOG(INFO) << __func__
+                << ": 5/6 GHz hotspot is disabled by feature flag, using 2.4 "
+                << "GHz band on channel " << selected_channel;
+    } else {
+      LOG(INFO) << __func__
+                << ": Device supports only 2.4 GHz, using 2.4 GHz band on "
+                << "channel " << selected_channel;
+    }
   }
 
   const int32_t fallback_channel_width =