A script to reset USB controllers

usb_reset

#!/usr/bin/env bash
#
# USB xHCI controller reset helper
# - Unbinds/rebinds the controller from/to xhci_hcd
# - Colors + Nerd Font icons chosen automatically by log level
# - --interactive: pick a controller from a list (uses fzf if available)
#
# Usage:
#   sudo reset-usb.sh [--interactive] [CONTROLLER_ID]
#   sudo reset-usb.sh --help
#

set -euo pipefail

# --- Config (defaults) ---
DRIVER="xhci_hcd"
CONTROLLER_DEFAULT="0000:00:14.0"
SLEEP_SECONDS=2

DRIVER_DIR="/sys/bus/pci/drivers/${DRIVER}"
UNBIND_PATH="${DRIVER_DIR}/unbind"
BIND_PATH="${DRIVER_DIR}/bind"

# --- Colors (respect NO_COLOR and only if stderr is a TTY) ---
if [[ -t 2 && -z "${NO_COLOR:-}" ]]; then
  COLOR_RED=$'\e[31m'
  COLOR_GREEN=$'\e[32m'
  COLOR_YELLOW=$'\e[33m'
  COLOR_BLUE=$'\e[34m'
  COLOR_DIM=$'\e[2m'
  COLOR_RESET=$'\e[0m'
else
  COLOR_RED=""; COLOR_GREEN=""; COLOR_YELLOW=""; COLOR_BLUE=""; COLOR_DIM=""; COLOR_RESET=""
fi

# --- Nerd Font Icons (fallback if not supported) ---
ICON_INFO=""
ICON_OK=""
ICON_WARN=""
ICON_ERR=""
ICON_USB=""

# crude fallback if glyphs won’t render
if ! printf "%b" "$ICON_OK" | LC_ALL=C grep -q . 2>/dev/null; then
  ICON_INFO="i"; ICON_OK="OK"; ICON_WARN="!"; ICON_ERR="X"; ICON_USB="USB"
fi

# --- Helpers to map level -> color/icon ---
_color_for_level() {
  case "${1^^}" in
    SUCCESS) printf "%s" "$COLOR_GREEN" ;;
    INFO)    printf "%s" "$COLOR_BLUE"  ;;
    WARN)    printf "%s" "$COLOR_YELLOW";;
    ERROR)   printf "%s" "$COLOR_RED"   ;;
    *)       printf "%s" "$COLOR_DIM"   ;;
  esac
}

_icon_for_level() {
  case "${1^^}" in
    SUCCESS) printf "%s" "$ICON_OK"   ;;
    INFO)    printf "%s" "$ICON_INFO" ;;
    WARN)    printf "%s" "$ICON_WARN" ;;
    ERROR)   printf "%s" "$ICON_ERR"  ;;
    *)       printf "%s" "$ICON_INFO" ;;
  esac
}

# --- Logging ---
log() { # usage: log LEVEL "message..."
  local level="${1:-INFO}"; shift || true
  local msg="${*:-}"
  local color; color="$(_color_for_level "$level")"
  local icon;  icon="$(_icon_for_level "$level")"

  # Timestamp dimmed, then restore the level color for the message
  printf "%b%s %b[%s]%b %b%s%b\n" \
    "$color" "$icon" \
    "$COLOR_DIM" "$(date '+%H:%M:%S')" "$COLOR_RESET" \
    "$color" "$msg" "$COLOR_RESET" >&2
}

die() {
  log ERROR "$*"
  exit 1
}

usage() {
  cat >&2 <<EOF
Reset an xHCI USB controller by unbinding/rebinding to ${DRIVER}.

${COLOR_DIM}Usage:${COLOR_RESET}
  sudo ${0##*/} [--interactive] [CONTROLLER_ID]
  sudo ${0##*/} --help

${COLOR_DIM}Examples:${COLOR_RESET}
  sudo ${0##*/}                    # uses default ${CONTROLLER_DEFAULT}
  sudo ${0##*/} 0000:03:00.0       # explicit controller
  sudo ${0##*/} --interactive      # pick from detected controllers

${COLOR_DIM}Notes:${COLOR_RESET}
- Must be run as root (or via sudo).
- You can whitelist this script in sudoers with NOPASSWD for convenience.
EOF
}

require_root() {
  [[ "${EUID}" -eq 0 ]] || die "Please run as root (sudo)."
}

check_paths() {
  [[ -w "$UNBIND_PATH" && -w "$BIND_PATH" ]] || die "Cannot access ${UNBIND_PATH} or ${BIND_PATH}. Is ${DRIVER} loaded?"
}

list_bound_controllers() {
  shopt -s nullglob
  local d
  for d in "${DRIVER_DIR}"/0000:*; do
    [[ -e "$d" ]] && basename "$d"
  done
  shopt -u nullglob
}

pick_controller_interactive() {
  mapfile -t items < <(list_bound_controllers)
  ((${#items[@]})) || die "No controllers bound to ${DRIVER} were found."

  if command -v fzf >/dev/null 2>&1; then
    printf "%s\n" "${items[@]}" | fzf --prompt="Select controller > " --height=40% --reverse --border || true
  else
    log INFO "fzf not found, using bash menu."
    local PS3="Select controller (1-${#items[@]} or 'q' to quit): "
    local choice
    select choice in "${items[@]}"; do
      [[ -n "${choice:-}" ]] && { echo "$choice"; break; }
      [[ "$REPLY" == "q" ]] && return 1
      echo "Invalid choice." >&2
    done
  fi
}

reset_controller() {
  local ctrl="$1"
  log WARN "Unbinding ${ICON_USB} controller ${ctrl} from driver ${DRIVER}..."
  echo "$ctrl" >"$UNBIND_PATH" || die "Failed to unbind ${ctrl}."

  sleep "$SLEEP_SECONDS"

  log INFO "Rebinding ${ICON_USB} controller ${ctrl} to driver ${DRIVER}..."
  echo "$ctrl" >"$BIND_PATH" || die "Failed to bind ${ctrl}."

  log SUCCESS "Controller ${ctrl} reset complete."
}

# --- Argument parsing ---
INTERACTIVE=false
CONTROLLER_ARG=""

while (( "$#" )); do
  case "$1" in
    -i|--interactive) INTERACTIVE=true ;;
    -h|--help) usage; exit 0 ;;
    --) shift; break ;;
    -*)
      die "Unknown option: $1. Use --help."
      ;;
    *)
      if [[ -z "$CONTROLLER_ARG" ]]; then
        CONTROLLER_ARG="$1"
      else
        die "Unexpected extra argument: $1"
      fi
      ;;
  esac
  shift
done

# --- Main ---
require_root
check_paths

if "$INTERACTIVE"; then
  SELECTED="$(pick_controller_interactive || true)"
  [[ -n "${SELECTED:-}" ]] || die "No controller selected."
  CONTROLLER="$SELECTED"
else
  CONTROLLER="${CONTROLLER_ARG:-$CONTROLLER_DEFAULT}"
fi

# Basic format hint (don't block if it doesn't match)
if [[ ! "$CONTROLLER" =~ ^[0-9a-fA-F]{4}:[0-9a-fA-F]{2}:[0-9a-fA-F]{2}\.[0-9a-fA-F]$ ]]; then
  log WARN "Controller ID '$CONTROLLER' doesn't look like a PCI address (domain:bus:slot.func). Proceeding anyway..."
fi

reset_controller "$CONTROLLER"