Resolve lints in the TTY module

kernel/src/device/tty/device.rs

@@ -1,7 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
 
-#![expect(unused_variables)]
-
 use crate::{
     events::IoEvents,
     fs::{
@@ -41,17 +39,17 @@ impl Device for TtyDevice {
 }
 
 impl Pollable for TtyDevice {
-    fn poll(&self, mask: IoEvents, poller: Option<&mut PollHandle>) -> IoEvents {
+    fn poll(&self, _mask: IoEvents, _poller: Option<&mut PollHandle>) -> IoEvents {
         IoEvents::empty()
     }
 }
 
 impl FileIo for TtyDevice {
-    fn read(&self, writer: &mut VmWriter) -> Result<usize> {
+    fn read(&self, _writer: &mut VmWriter) -> Result<usize> {
         return_errno_with_message!(Errno::EINVAL, "cannot read tty device");
     }
 
-    fn write(&self, reader: &mut VmReader) -> Result<usize> {
+    fn write(&self, _reader: &mut VmReader) -> Result<usize> {
         return_errno_with_message!(Errno::EINVAL, "cannot write tty device");
     }
 }

kernel/src/device/tty/driver.rs

@@ -1,7 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
 
-#![expect(dead_code)]
-
 use ostd::mm::{Infallible, VmReader};
 use spin::Once;
 
@@ -86,11 +84,6 @@ fn console_input_callback(mut reader: VmReader<Infallible>) {
     }
 }
 
-fn serial_input_callback(item: u8) {
-    let tty_driver = get_tty_driver();
-    tty_driver.push_char(item);
-}
-
 fn get_tty_driver() -> &'static TtyDriver {
     TTY_DRIVER.get().unwrap()
 }

kernel/src/device/tty/line_discipline.rs

@@ -1,7 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
 
-#![expect(unused_variables)]
-
 use alloc::format;
 
 use ostd::{
@@ -235,7 +233,7 @@ impl LineDiscipline {
                 let ctrl_char = format!("^{}", get_printable_char(ch));
                 echo_callback(&ctrl_char);
             }
-            item => {}
+            _ => {}
         }
     }
 
@@ -254,8 +252,6 @@ impl LineDiscipline {
             (vmin, vtime)
         };
         let read_len = {
-            let len = self.read_buffer.lock().len();
-            let max_read_len = len.min(dst.len());
             if vmin == 0 && vtime == 0 {
                 // poll read
                 self.poll_read(dst)
@@ -402,11 +398,6 @@ fn get_printable_char(ctrl_char: u8) -> char {
     char::from_u32((ctrl_char + b'A' - 1) as u32).unwrap()
 }
 
-enum PolleeType {
-    Add,
-    Del,
-}
-
 struct LineDisciplineWorkPara {
     kernel_signal: Option<KernelSignal>,
 }

kernel/src/device/tty/mod.rs

@@ -1,7 +1,5 @@
 // SPDX-License-Identifier: MPL-2.0
 
-#![expect(dead_code)]
-
 use ostd::early_print;
 use spin::Once;
 
@@ -39,6 +37,7 @@ pub(super) fn init() {
 
 pub struct Tty {
     /// tty_name
+    #[expect(unused)]
     name: CString,
     /// line discipline
     ldisc: Arc<LineDiscipline>,