sorry,the patch seems to be corrupt,I will resubmit the patch
------------------Original------------------ From: gregkh <gre...@linuxfoundation.org> To: li hao10307857; Cc: jirislaby <jirisl...@kernel.org>;linuxppc-dev <linuxppc-dev@lists.ozlabs.org>;linux-kernel <linux-ker...@vger.kernel.org>; Date: 2024/04/11 22:03 Subject: Re: [PATCH] tty: hvc: wakeup hvc console immediately when needed On Thu, Apr 11, 2024 at 09:50:17PM +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. > > Signed-off-by: Li Hao Did checkpatch say this was ok?