n_tty: Remove reader wakeups for TTY_BREAK/TTY_PARITY chars
PATCH 1/1 n_tty: Remove reader wakeups for TTY_BREAK/TTY_PARITY chars
Waking the reader immediately upon receipt of TTY_BREAK or TTY_PARITY chars has no effect on the outcome of read():
1. Only non-canonical/EXTPROC mode applies since canonical mode will not return data until a line termination is received anyway
2. EXTPROC mode - the reader will always be woken by the input worker
3. Non-canonical modes
a. MIN == 0, TIME == 0
b. MIN == 0, TIME > 0
c. MIN > 0, TIME > 0
minimum_to_wake is always 1 in these modes so the reader will always be woken by the input worker
d. MIN > 0, TIME == 0
although the reader will not be woken by the input worker unless the minimum data is received, the reader would not otherwise have returned the received data
--- drivers/tty/n_tty.c | 4 ---- 1 file changed, 4 deletions(-)
drivers/tty/n_tty.c +0 -4
@@ -1180,8 +1180,6 @@ static void n_tty_receive_break(struct tty_struct *tty)put_tty_queue ('\0' , ldata); }put_tty_queue ('\0' , ldata); -if (waitqueue_active (&tty->read_wait)) -wake_up_interruptible_poll (&tty->read_wait,POLLIN ); }/**
@@ -1238,8 +1236,6 @@ static void n_tty_receive_parity_error(struct tty_struct *tty, unsigned char c)put_tty_queue ('\0' , ldata); }else put_tty_queue (c, ldata); -if (waitqueue_active (&tty->read_wait)) -wake_up_interruptible_poll (&tty->read_wait,POLLIN ); } static void
Signature · 1 line
2.6.1