diff --git a/bin/usb-client b/bin/usb-client
index 0e01fa2..fa36f0b 100755
Binary files a/bin/usb-client and b/bin/usb-client differ
diff --git a/bin/usb-relay b/bin/usb-relay
index 9a263dd..6d6fdb8 100755
Binary files a/bin/usb-relay and b/bin/usb-relay differ
diff --git a/internal/client/socket_linux.go b/internal/client/socket_linux.go
index 65a0769..ca83e81 100644
--- a/internal/client/socket_linux.go
+++ b/internal/client/socket_linux.go
@@ -7,6 +7,7 @@ import (
 	"log"
 	"os"
 	"path/filepath"
+	"strings"
 	"time"
 
 	"golang.org/x/sys/unix"
@@ -35,48 +36,58 @@ func fdToFile(fd int, name string) *os.File {
 // VHCI-created devices don't get normal udev rules applied, so they
 // default to root-only access.
 func fixVHCIDevicePermissions(port int) {
-	// Wait for the device to finish enumerating and create device nodes
-	// The kernel needs time to enumerate descriptors and bind drivers
-	for attempt := 0; attempt < 10; attempt++ {
+	// Wait for the device to finish enumerating and create device nodes.
+	// The kernel needs time to enumerate descriptors and bind drivers.
+	for attempt := 0; attempt < 15; attempt++ {
 		time.Sleep(500 * time.Millisecond)
 
-		// Find device nodes created by this VHCI port
-		// VHCI creates devices under /sys/devices/platform/vhci_hcd.0/usbN/
-		// We look for video4linux devices
-		matches, _ := filepath.Glob("/sys/devices/platform/vhci_hcd.0/usb*/*/video4linux/video*")
-		for _, m := range matches {
-			devName := filepath.Base(m)
-			devPath := "/dev/" + devName
-			if _, err := os.Stat(devPath); err == nil {
+		found := false
+
+		// Walk the VHCI sysfs tree to find device nodes at any depth.
+		// Paths look like: vhci_hcd.0/usb3/3-1/3-1:1.0/video4linux/video0
+		filepath.WalkDir("/sys/devices/platform/vhci_hcd.0", func(path string, d os.DirEntry, err error) error {
+			if err != nil {
+				return nil
+			}
+
+			dir := filepath.Dir(path)
+			parent := filepath.Base(dir)
+
+			// video4linux devices → /dev/videoN
+			if parent == "video4linux" && strings.HasPrefix(d.Name(), "video") {
+				devPath := "/dev/" + d.Name()
+				if err := os.Chmod(devPath, 0666); err == nil {
+					log.Printf("[use] set permissions 0666 on %s", devPath)
+					found = true
+				}
+			}
+
+			// sound devices → /dev/snd/*
+			if parent == "sound" && strings.HasPrefix(d.Name(), "card") {
+				// For sound cards, chmod all related device nodes
+				sndDir := filepath.Join(path, "device")
+				if _, err := os.Stat(sndDir); err == nil {
+					filepath.WalkDir("/dev/snd", func(sndPath string, sd os.DirEntry, err error) error {
+						if err == nil && !sd.IsDir() {
+							os.Chmod(sndPath, 0666)
+						}
+						return nil
+					})
+				}
+			}
+
+			// input devices → /dev/input/eventN
+			if strings.HasPrefix(d.Name(), "event") && strings.Contains(path, "/input/input") {
+				devPath := "/dev/input/" + d.Name()
 				if err := os.Chmod(devPath, 0666); err == nil {
 					log.Printf("[use] set permissions 0666 on %s", devPath)
 				}
 			}
-		}
 
-		// Also check for other common device types (input, sound, etc.)
-		for _, subsys := range []string{"sound/card*", "input/input*/event*"} {
-			sysMatches, _ := filepath.Glob("/sys/devices/platform/vhci_hcd.0/usb*/*/" + subsys)
-			for _, m := range sysMatches {
-				devName := filepath.Base(m)
-				devPath := "/dev/" + devName
-				// For sound devices, also check /dev/snd/
-				if _, err := os.Stat(devPath); err == nil {
-					os.Chmod(devPath, 0666)
-				}
-				devPath = "/dev/snd/" + devName
-				if _, err := os.Stat(devPath); err == nil {
-					os.Chmod(devPath, 0666)
-				}
-			}
-		}
+			return nil
+		})
 
-		if attempt == 0 {
-			continue // first iteration: always wait more
-		}
-
-		// Check if we found any video devices
-		if len(matches) > 0 {
+		if attempt >= 2 && found {
 			return
 		}
 	}
diff --git a/internal/client/use.go b/internal/client/use.go
index 37e6919..112126f 100644
--- a/internal/client/use.go
+++ b/internal/client/use.go
@@ -272,6 +272,7 @@ func (um *UseManager) tunnelReadLoop(tunnel *useTunnel) {
 		}
 
 		if err := um.client.SendTunnelData(tunnel.id, buf[:n]); err != nil {
+			log.Printf("[use] tunnel send error: %v", err)
 			return
 		}
 	}
@@ -326,11 +327,17 @@ func (um *UseManager) handleTunnelData(tunnelID string, data []byte) {
 	um.mu.RUnlock()
 
 	if !exists {
+		log.Printf("[use] tunnel data for unknown tunnel %s (%d bytes)", tunnelID[:8], len(data))
 		return
 	}
 
 	// Write to the tunnel socket (relay -> VHCI)
-	tunnel.conn.Write(data)
+	n, err := tunnel.conn.Write(data)
+	if err != nil {
+		log.Printf("[use] tunnel write error: %v", err)
+	} else if n != len(data) {
+		log.Printf("[use] tunnel short write: %d/%d", n, len(data))
+	}
 }
 
 func (um *UseManager) handleClientLeft(msg *protocol.ClientLeft) {
diff --git a/internal/usbip/server.go b/internal/usbip/server.go
index 449c82b..f00c5cd 100644
--- a/internal/usbip/server.go
+++ b/internal/usbip/server.go
@@ -421,10 +421,15 @@ func (s *Server) handleCmdSubmit(r io.Reader, hdr *URBHeader, retChan chan<- []b
 				5000, buf,
 			)
 			if err != nil {
+				log.Printf("[usbip-server] CTRL OUT seq=%d failed: %v", hdr.SeqNum, err)
 				status = -32 // -EPIPE
+			} else {
+				log.Printf("[usbip-server] CTRL OUT seq=%d OK (bmReqType=0x%02x bReq=0x%02x wVal=0x%04x)",
+					hdr.SeqNum, bmRequestType, bRequest, wValue)
 			}
 		}
 
+		log.Printf("[usbip-server] CTRL OUT seq=%d → response status=%d", hdr.SeqNum, status)
 		resp, err := BuildRetSubmit(hdr.SeqNum, hdr.DevID, hdr.Direction, hdr.Endpoint, status, nil)
 		if err != nil {
 			return err
@@ -559,6 +564,8 @@ func (s *Server) handleCmdUnlink(r io.Reader, hdr *URBHeader, retChan chan<- []b
 		return err
 	}
 
+	log.Printf("[usbip-server] UNLINK seq=%d target_seq=%d", hdr.SeqNum, body.UnlinkSeqNum)
+
 	s.mu.Lock()
 	pending, exists := s.pendingURBs[body.UnlinkSeqNum]
 	if exists {