fix: apply all LoRa config changes live without rebooting (#9962)

* fix: apply all LoRa config changes live without rebooting

All LoRa radio settings (SF, BW, CR, frequency, power, preset,
sx126x_rx_boosted_gain) now apply immediately via reconfigure()
without requiring a node reboot.

- AdminModule: requiresReboot = false for all LoRa config changes;
  LoRa changes were already handled by the configChanged observer
  calling reconfigure() but the reboot flag was set unnecessarily
- AdminModule: validate LORA_24 region against radio hardware at
  config time; reject with BAD_REQUEST if hardware lacks 2.4 GHz
  capability (wideLora() returns false or no radio instance)
- SX126xInterface/LR11x0Interface: apply sx126x_rx_boosted_gain in
  reconfigure(); register 0x08AC is writable in STDBY mode (SX1261/2
  datasheet §9.6); retention registers written so setting survives
  warm-sleep cycles; log warning on setter failure
- DebugRenderer: show BW/SF/CR on debug screen when custom modem is
  active instead of the preset name
- DisplayFormatters: clarify comment on getModemPresetDisplayName

* fix: remove redundant reboot after LoRa config changes in on-device menus

Region, frequency slot, and radio preset pickers in MenuHandler all
called reloadConfig() then immediately set rebootAtMsec. reloadConfig()
already fires the configChanged observer which calls reconfigure(), so
the forced reboot was unnecessary — same rationale as the parent commit.

* fix: guard LORA_24 region selection against hardware capability in on-device menu

Without a reboot, reconfigure() now applies region changes directly.
Previously getRadio() caught the LORA_24-on-sub-GHz mismatch post-reboot
and reverted to UNSET — that safety net is gone. Add an explicit wideLora()
check in LoraRegionPicker so sub-GHz-only hardware silently ignores LORA_24
selection instead of attempting a live reconfigure with an invalid frequency.

---------

Co-authored-by: elwimen <elwimen@users.noreply.github.com>
Co-authored-by: Ben Meadors <benmmeadors@gmail.com>

src/DisplayFormatters.cpp

@@ -4,7 +4,8 @@ const char *DisplayFormatters::getModemPresetDisplayName(meshtastic_Config_LoRaC
                                                          bool usePreset)
 {
 
-    // If use_preset is false, always return "Custom"
+    // If use_preset is false, always return "Custom" — callers such as RadioInterface and Channels
+    // rely on this being a stable literal for channel-name hashing and default-channel detection.
     if (!usePreset) {
         return "Custom";
     }

src/graphics/draw/DebugRenderer.cpp

@@ -408,7 +408,16 @@ void drawLoRaFocused(OLEDDisplay *display, OLEDDisplayUiState *state, int16_t x,
     display->drawString(nameX, getTextPositions(display)[line++], device_role);
 
     // === Third Row: Radio Preset ===
-    auto mode = DisplayFormatters::getModemPresetDisplayName(config.lora.modem_preset, false, config.lora.use_preset);
+    // For custom modem settings show the actual parameters; for presets use the preset name.
+    char modeStr[16];
+    if (!config.lora.use_preset) {
+        snprintf(modeStr, sizeof(modeStr), "BW%u-SF%u-CR%u", static_cast<unsigned>(config.lora.bandwidth),
+                 static_cast<unsigned>(config.lora.spread_factor), static_cast<unsigned>(config.lora.coding_rate));
+    } else {
+        strncpy(modeStr, DisplayFormatters::getModemPresetDisplayName(config.lora.modem_preset, false, true),
+                sizeof(modeStr) - 1);
+        modeStr[sizeof(modeStr) - 1] = '\0';
+    }
 
     char regionradiopreset[25];
     const char *region = myRegion ? myRegion->name : NULL;
@@ -416,7 +425,7 @@ void drawLoRaFocused(OLEDDisplay *display, OLEDDisplayUiState *state, int16_t x,
         if (currentResolution == ScreenResolution::UltraLow) {
             snprintf(regionradiopreset, sizeof(regionradiopreset), "%s", region);
         } else {
-            snprintf(regionradiopreset, sizeof(regionradiopreset), "%s/%s", region, mode);
+            snprintf(regionradiopreset, sizeof(regionradiopreset), "%s/%s", region, modeStr);
         }
     }
     textWidth = display->getStringWidth(regionradiopreset);

src/graphics/draw/MenuHandler.cpp

@@ -18,6 +18,7 @@
 #include "main.h"
 #include "mesh/Default.h"
 #include "mesh/MeshTypes.h"
+#include "mesh/RadioLibInterface.h"
 #include "modules/AdminModule.h"
 #include "modules/CannedMessageModule.h"
 #include "modules/ExternalNotificationModule.h"
@@ -160,6 +161,14 @@ void menuHandler::LoraRegionPicker(uint32_t duration)
                 return;
             }
 
+            // Guard: without a reboot, reconfigure() applies the region directly.
+            // Reject LORA_24 on sub-GHz-only hardware — getRadio() used to catch this post-reboot.
+            if (selectedRegion == meshtastic_Config_LoRaConfig_RegionCode_LORA_24 &&
+                !(RadioLibInterface::instance && RadioLibInterface::instance->wideLora())) {
+                LOG_WARN("Radio hardware does not support 2.4 GHz; ignoring LORA_24 selection");
+                return;
+            }
+
             config.lora.region = selectedRegion;
             auto changes = SEGMENT_CONFIG;
 
@@ -181,7 +190,6 @@ void menuHandler::LoraRegionPicker(uint32_t duration)
             }
 
             service->reloadConfig(changes);
-            rebootAtMsec = (millis() + DEFAULT_REBOOT_SECONDS * 1000);
         });
 
     bannerOptions.durationMs = duration;
@@ -300,7 +308,6 @@ void menuHandler::FrequencySlotPicker()
 
         config.lora.channel_num = selected;
         service->reloadConfig(SEGMENT_CONFIG);
-        rebootAtMsec = (millis() + DEFAULT_REBOOT_SECONDS * 1000);
     };
 
     screen->showOverlayBanner(bannerOptions);
@@ -339,7 +346,6 @@ void menuHandler::radioPresetPicker()
             config.lora.channel_num = 0;        // Reset to default channel for the preset
             config.lora.override_frequency = 0; // Clear any custom frequency
             service->reloadConfig(SEGMENT_CONFIG);
-            rebootAtMsec = (millis() + DEFAULT_REBOOT_SECONDS * 1000);
         });
 
     screen->showOverlayBanner(bannerOptions);

src/mesh/LR11x0Interface.cpp

@@ -192,6 +192,11 @@ template <typename T> bool LR11x0Interface<T>::reconfigure()
     err = lora.setOutputPower(power);
     assert(err == RADIOLIB_ERR_NONE);
 
+    // Apply RX gain mode — valid in STDBY, matches resetAGC() pattern
+    err = lora.setRxBoostedGainMode(config.lora.sx126x_rx_boosted_gain);
+    if (err != RADIOLIB_ERR_NONE)
+        LOG_WARN("LR11x0 setRxBoostedGainMode %s%d", radioLibErr, err);
+
     startReceive(); // restart receiving
 
     return RADIOLIB_ERR_NONE;

src/mesh/SX126xInterface.cpp

@@ -253,6 +253,11 @@ template <typename T> bool SX126xInterface<T>::reconfigure()
         LOG_ERROR("SX126X setOutputPower %s%d", radioLibErr, err);
     assert(err == RADIOLIB_ERR_NONE);
 
+    // Apply RX gain mode — valid in STDBY (datasheet §9.6), matches resetAGC() pattern
+    err = lora.setRxBoostedGainMode(config.lora.sx126x_rx_boosted_gain);
+    if (err != RADIOLIB_ERR_NONE)
+        LOG_WARN("SX126X setRxBoostedGainMode %s%d", radioLibErr, err);
+
     startReceive(); // restart receiving
 
     return RADIOLIB_ERR_NONE;

src/modules/AdminModule.cpp

@@ -26,6 +26,7 @@
 #include "MeshRadio.h"
 #include "RadioInterface.h"
 #include "TypeConversions.h"
+#include "mesh/RadioLibInterface.h"
 
 #if !MESHTASTIC_EXCLUDE_MQTT
 #include "mqtt/MQTT.h"
@@ -198,10 +199,35 @@ bool AdminModule::handleReceivedProtobuf(const meshtastic_MeshPacket &mp, meshta
         handleSetOwner(r->set_owner);
         break;
 
-    case meshtastic_AdminMessage_set_config_tag:
+    case meshtastic_AdminMessage_set_config_tag: {
         LOG_DEBUG("Client set config");
-        handleSetConfig(r->set_config, fromOthers);
+
+        // Non-LoRa configs need no further validation.
+        if (r->set_config.which_payload_variant != meshtastic_Config_lora_tag) {
+            LOG_DEBUG("Non-LoRa config, applying directly");
+            handleSetConfig(r->set_config, fromOthers);
+            break;
+        }
+
+        // Only LORA_24 requires hardware capability validation.
+        if (r->set_config.payload_variant.lora.region != meshtastic_Config_LoRaConfig_RegionCode_LORA_24) {
+            LOG_DEBUG("LoRa config, region is not LORA_24, applying directly");
+            handleSetConfig(r->set_config, fromOthers);
+            break;
+        }
+
+        // Hardware supports 2.4 GHz — apply the config.
+        // Fail closed: null instance is treated as incapable.
+        if (RadioLibInterface::instance && RadioLibInterface::instance->wideLora()) {
+            LOG_DEBUG("LORA_24 requested, radio hardware supports 2.4 GHz, applying");
+            handleSetConfig(r->set_config, fromOthers);
+            break;
+        }
+
+        LOG_WARN("Radio hardware does not support 2.4 GHz; rejecting LORA_24 region");
+        myReply = allocErrorResponse(meshtastic_Routing_Error_BAD_REQUEST, &mp);
         break;
+    }
 
     case meshtastic_AdminMessage_set_module_config_tag:
         LOG_DEBUG("Client set module config");
@@ -816,17 +842,9 @@ void AdminModule::handleSetConfig(const meshtastic_Config &c, bool fromOthers)
             //  use_preset and bandwidth are coerced into valid values by the check.
         }
 
-        // If no lora radio parameters change, don't need to reboot
-        if (oldLoraConfig.use_preset == validatedLora.use_preset && oldLoraConfig.region == validatedLora.region &&
-            oldLoraConfig.modem_preset == validatedLora.modem_preset && oldLoraConfig.bandwidth == validatedLora.bandwidth &&
-            oldLoraConfig.spread_factor == validatedLora.spread_factor &&
-            oldLoraConfig.coding_rate == validatedLora.coding_rate && oldLoraConfig.tx_power == validatedLora.tx_power &&
-            oldLoraConfig.frequency_offset == validatedLora.frequency_offset &&
-            oldLoraConfig.override_frequency == validatedLora.override_frequency &&
-            oldLoraConfig.channel_num == validatedLora.channel_num &&
-            oldLoraConfig.sx126x_rx_boosted_gain == validatedLora.sx126x_rx_boosted_gain) {
-            requiresReboot = false;
-        }
+        // All LoRa radio changes apply live via configChanged observer → reconfigure().
+        // reconfigure() puts the radio in standby, reprograms all modem parameters, and restarts receive.
+        requiresReboot = false;
 
 #if defined(ARCH_PORTDUINO)
         // If running on portduino and using SimRadio, do not require reboot