On Mon, Apr 15, 2024 at 03:26:17PM +0800, li.ha...@zte.com.cn wrote: > From: Li Hao <li.ha...@zte.com.cn> > > Cancel the do_wakeup flag in hvc_struct, and change it to immediately > wake up tty when hp->n_outbuf is 0 in hvc_push(). > > When we receive a key input character, the interrupt handling function > hvc_handle_interrupt() will be executed, and the echo thread > flush_to_ldisc() will be added to the queue. > > If the user is currently using tcsetattr(), a hang may occur. tcsetattr() > enters kernel and waits for hp->n_outbuf to become 0 via > tty_wait_until_sent(). If the echo thread finishes executing before > reaching tty_wait_until_sent (for example, put_chars() takes too long), > it will cause while meeting the wakeup condition (hp->do_wakeup = 1), > tty_wait_until_sent() cannot be woken up (missed the tty_wakeup() of > this round's tty_poll). Unless the next key input character comes, > hvc_poll will be executed, and tty_wakeup() will be performed through > the do_wakeup flag. > > v1->v2: > Some fixes according to: > https://lore.kernel.org/all/75dff5cd-7b0e-4039-9157-8bf10cf7b...@kernel.org/ > use tty_port_tty_wakeup() instead of tty_wakeup() to wake up tty
As per the documentation, the v1... stuff needs to go below the --- line so git will strip it away. Please fix up and send a v3. thanks, greg k-h
