refactor: 删除部分多余的代码和注释

src/otg/configfs.rs

@@ -1,5 +1,3 @@
-//! ConfigFS file operations for USB Gadget
-
 use std::fs::{self, File, OpenOptions};
 use std::io::Write;
 use std::path::Path;
@@ -7,34 +5,18 @@ use std::process::Command;
 
 use crate::error::{AppError, Result};
 
-/// ConfigFS base path for USB gadgets
 pub const CONFIGFS_PATH: &str = "/sys/kernel/config/usb_gadget";
-
-/// Default gadget name
 pub const DEFAULT_GADGET_NAME: &str = "one-kvm";
-
-/// USB Vendor ID (Linux Foundation) - default value
 pub const DEFAULT_USB_VENDOR_ID: u16 = 0x1d6b;
-
-/// USB Product ID (Multifunction Composite Gadget) - default value
 pub const DEFAULT_USB_PRODUCT_ID: u16 = 0x0104;
-
-/// USB device version - default value
 pub const DEFAULT_USB_BCD_DEVICE: u16 = 0x0100;
-
-/// USB spec version (USB 2.0)
 pub const USB_BCD_USB: u16 = 0x0200;
 
-/// Check if ConfigFS is available
 pub fn is_configfs_available() -> bool {
     Path::new(CONFIGFS_PATH).exists()
 }
 
-/// Ensure libcomposite support is available for USB gadget operations.
-///
-/// This is a best-effort runtime fallback for systems where `libcomposite`
-/// is built as a module and not loaded yet. It does not try to mount configfs;
-/// mounting remains an explicit system responsibility.
+/// Loads `libcomposite` if needed; does not mount configfs.
 pub fn ensure_libcomposite_loaded() -> Result<()> {
     if is_configfs_available() {
         return Ok(());
@@ -66,7 +48,6 @@ pub fn ensure_libcomposite_loaded() -> Result<()> {
     }
 }
 
-/// Find available UDC (USB Device Controller)
 pub fn find_udc() -> Option<String> {
     let udc_path = Path::new("/sys/class/udc");
     if !udc_path.exists() {
@@ -80,40 +61,17 @@ pub fn find_udc() -> Option<String> {
         .next()
 }
 
-/// Check if UDC is known to have low endpoint resources
 pub fn is_low_endpoint_udc(name: &str) -> bool {
     let name = name.to_ascii_lowercase();
     name.contains("musb") || name.contains("musb-hdrc")
 }
 
-/// Resolve preferred UDC name if available, otherwise auto-detect
-pub fn resolve_udc_name(preferred: Option<&str>) -> Option<String> {
-    if let Some(name) = preferred {
-        let path = Path::new("/sys/class/udc").join(name);
-        if path.exists() {
-            return Some(name.to_string());
-        }
-    }
-    find_udc()
-}
-
-/// Write string content to a file
-///
-/// For sysfs files, this function appends a newline and flushes
-/// to ensure the kernel processes the write immediately.
-///
-/// IMPORTANT: sysfs attributes require a single atomic write() syscall.
-/// The kernel processes the value on the first write(), so we must
-/// build the complete buffer (including newline) before writing.
+/// Sysfs/configfs: one write syscall with final buffer (incl. newline when needed).
 pub fn write_file(path: &Path, content: &str) -> Result<()> {
-    // For sysfs files (especially write-only ones like forced_eject),
-    // we need to use simple O_WRONLY without O_TRUNC
-    // O_TRUNC may fail on special files or require read permission
     let mut file = OpenOptions::new()
         .write(true)
         .open(path)
         .or_else(|e| {
-            // If open fails, try create (for regular files)
             if path.exists() {
                 Err(e)
             } else {
@@ -122,9 +80,6 @@ pub fn write_file(path: &Path, content: &str) -> Result<()> {
         })
         .map_err(|e| AppError::Internal(format!("Failed to open {}: {}", path.display(), e)))?;
 
-    // Build complete buffer with newline, then write in single syscall.
-    // This is critical for sysfs - multiple write() calls may cause
-    // the kernel to only process partial data or return EINVAL.
     let data: std::borrow::Cow<[u8]> = if content.ends_with('\n') {
         content.as_bytes().into()
     } else {
@@ -136,14 +91,12 @@ pub fn write_file(path: &Path, content: &str) -> Result<()> {
     file.write_all(&data)
         .map_err(|e| AppError::Internal(format!("Failed to write to {}: {}", path.display(), e)))?;
 
-    // Explicitly flush to ensure sysfs processes the write
     file.flush()
         .map_err(|e| AppError::Internal(format!("Failed to flush {}: {}", path.display(), e)))?;
 
     Ok(())
 }
 
-/// Write binary content to a file
 pub fn write_bytes(path: &Path, data: &[u8]) -> Result<()> {
     let mut file = File::create(path)
         .map_err(|e| AppError::Internal(format!("Failed to create {}: {}", path.display(), e)))?;
@@ -154,14 +107,6 @@ pub fn write_bytes(path: &Path, data: &[u8]) -> Result<()> {
     Ok(())
 }
 
-/// Read string content from a file
-pub fn read_file(path: &Path) -> Result<String> {
-    fs::read_to_string(path)
-        .map(|s| s.trim().to_string())
-        .map_err(|e| AppError::Internal(format!("Failed to read {}: {}", path.display(), e)))
-}
-
-/// Create directory if not exists
 pub fn create_dir(path: &Path) -> Result<()> {
     fs::create_dir_all(path).map_err(|e| {
         AppError::Internal(format!(
@@ -172,7 +117,6 @@ pub fn create_dir(path: &Path) -> Result<()> {
     })
 }
 
-/// Remove directory
 pub fn remove_dir(path: &Path) -> Result<()> {
     if path.exists() {
         fs::remove_dir(path).map_err(|e| {
@@ -186,7 +130,6 @@ pub fn remove_dir(path: &Path) -> Result<()> {
     Ok(())
 }
 
-/// Remove file
 pub fn remove_file(path: &Path) -> Result<()> {
     if path.exists() {
         fs::remove_file(path).map_err(|e| {
@@ -196,7 +139,6 @@ pub fn remove_file(path: &Path) -> Result<()> {
     Ok(())
 }
 
-/// Create symlink
 pub fn create_symlink(src: &Path, dest: &Path) -> Result<()> {
     std::os::unix::fs::symlink(src, dest).map_err(|e| {
         AppError::Internal(format!(