From dafebacdfd306c924827aeab48b3e5519fa0bc89 Mon Sep 17 00:00:00 2001
From: Siyuan <siyuan@buildjet.com>
Date: Wed, 5 Nov 2025 15:43:10 +0000
Subject: [PATCH] feat: reset USB gadget if needed

---
 internal/usbgadget/config.go | 38 ++++++++++++++++++++++++------------
 jsonrpc.go                   | 10 +++++-----
 usb_mass_storage.go          |  2 +-
 3 files changed, 32 insertions(+), 18 deletions(-)

diff --git a/internal/usbgadget/config.go b/internal/usbgadget/config.go
index 6d1bd391..8cbdf081 100644
--- a/internal/usbgadget/config.go
+++ b/internal/usbgadget/config.go
@@ -177,7 +177,7 @@ func (u *UsbGadget) Init() error {
 
 	u.udc = udcs[0]
 
-	err := u.configureUsbGadget(false)
+	err := u.configureUsbGadget(false, true)
 	if err != nil {
 		return u.logError("unable to initialize USB stack", err)
 	}
@@ -185,13 +185,13 @@ func (u *UsbGadget) Init() error {
 	return nil
 }
 
-func (u *UsbGadget) UpdateGadgetConfig() error {
+func (u *UsbGadget) UpdateGadgetConfig(resetUsbIfNeeded bool) error {
 	u.configLock.Lock()
 	defer u.configLock.Unlock()
 
 	u.loadGadgetConfig()
 
-	err := u.configureUsbGadget(true)
+	err := u.configureUsbGadget(true, resetUsbIfNeeded)
 	if err != nil {
 		return u.logError("unable to update gadget config", err)
 	}
@@ -199,14 +199,28 @@ func (u *UsbGadget) UpdateGadgetConfig() error {
 	return nil
 }
 
-func (u *UsbGadget) configureUsbGadget(resetUsb bool) error {
-	return u.WithTransaction(func() error {
-		u.tx.MountConfigFS()
-		u.tx.CreateConfigPath()
-		u.tx.WriteGadgetConfig()
-		if resetUsb {
-			u.tx.RebindUsb(true)
+func (u *UsbGadget) configureUsbGadget(resetUsb bool, resetUsbIfNeeded bool) error {
+	f := func(resetUsbBefore bool, resetUsbAfter bool) func() error {
+		return func() error {
+			if resetUsbBefore {
+				u.tx.RebindUsb(true)
+			}
+			u.tx.MountConfigFS()
+			u.tx.CreateConfigPath()
+			u.tx.WriteGadgetConfig()
+			if resetUsbAfter {
+				u.tx.RebindUsb(true)
+			}
+			return nil
 		}
-		return nil
-	})
+	}
+
+	// initial attempt to configure the gadget
+	err := u.WithTransaction(f(false, resetUsb))
+	if err != nil && !resetUsbIfNeeded {
+		return err
+	}
+
+	// if the initial attempt failed, try to configure the gadget again with the resetUsb flag
+	return u.WithTransaction(f(true, resetUsb))
 }
diff --git a/jsonrpc.go b/jsonrpc.go
index 5ed90a7a..4d8695c2 100644
--- a/jsonrpc.go
+++ b/jsonrpc.go
@@ -678,7 +678,7 @@ func rpcSetUsbConfig(usbConfig usbgadget.Config) error {
 	LoadConfig()
 	config.UsbConfig = &usbConfig
 	gadget.SetGadgetConfig(config.UsbConfig)
-	return updateUsbRelatedConfig()
+	return updateUsbRelatedConfig(false)
 }
 
 func rpcGetWakeOnLanDevices() ([]WakeOnLanDevice, error) {
@@ -890,8 +890,8 @@ func rpcGetUsbDevices() (usbgadget.Devices, error) {
 	return *config.UsbDevices, nil
 }
 
-func updateUsbRelatedConfig() error {
-	if err := gadget.UpdateGadgetConfig(); err != nil {
+func updateUsbRelatedConfig(resetUsbIfNeeded bool) error {
+	if err := gadget.UpdateGadgetConfig(resetUsbIfNeeded); err != nil {
 		return fmt.Errorf("failed to write gadget config: %w", err)
 	}
 	if err := SaveConfig(); err != nil {
@@ -903,7 +903,7 @@ func updateUsbRelatedConfig() error {
 func rpcSetUsbDevices(usbDevices usbgadget.Devices) error {
 	config.UsbDevices = &usbDevices
 	gadget.SetGadgetDevices(config.UsbDevices)
-	return updateUsbRelatedConfig()
+	return updateUsbRelatedConfig(false)
 }
 
 func rpcSetUsbDeviceState(device string, enabled bool) error {
@@ -920,7 +920,7 @@ func rpcSetUsbDeviceState(device string, enabled bool) error {
 		return fmt.Errorf("invalid device: %s", device)
 	}
 	gadget.SetGadgetDevices(config.UsbDevices)
-	return updateUsbRelatedConfig()
+	return updateUsbRelatedConfig(false)
 }
 
 func rpcSetCloudUrl(apiUrl string, appUrl string) error {
diff --git a/usb_mass_storage.go b/usb_mass_storage.go
index 0f1f4b93..9a112e3a 100644
--- a/usb_mass_storage.go
+++ b/usb_mass_storage.go
@@ -66,7 +66,7 @@ func setMassStorageMode(cdrom bool) error {
 		return nil
 	}
 
-	return gadget.UpdateGadgetConfig()
+	return gadget.UpdateGadgetConfig(true)
 }
 
 func mountImage(imagePath string) error {