Hello kernel experts and users, I'm trying to boot linux-5.10.0-rc5 on our arm64 board (using neoverse-v1 core). After the shell comes up, when I press enter key at the prompt, it gives me another prompt. But when I press enter key again, it stops responding. After inspecting where the program hangs, I found it hangs in function tty_set_termios while downing the rwsem. Please see below where I marked "<===== this line "". (in file drivers/tty/tty_ioctl.c) int tty_set_termios(struct tty_struct *tty, struct ktermios *new_termios) { struct ktermios old_termios; struct tty_ldisc *ld; WARN_ON(tty->driver->type == TTY_DRIVER_TYPE_PTY && tty->driver->subtype == PTY_TYPE_MASTER); /* * Perform the actual termios internal changes under lock. */ /* FIXME: we need to decide on some locking/ordering semantics for the set_termios notification eventually */ down_write(&tty->termios_rwsem); <====== this line old_termios = tty->termios; tty->termios = *new_termios; unset_locked_termios(tty, &old_termios); I have to do some research on tty, line discpline, termios, and rw semaphores etc. but could anyone give me any suggestion on what can be going wrong? Or what to check first? Any suggestion will be really appreciated. Thank you! Chan Kim _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies