hvc_console: Escape magic sysrq key

The ctrl-o (^O) is a common control key used by several applications,
such as vim, but hvc_console uses ^O as the magic-sysrq key.  This
commit allows users to send ^O to applications by pressing ^O twice
in succession.

To implement this, this commit introduces a check if ^O is pressed
again if the sysrq_pressed variable is already set.  In this case,
clear sysrq_pressed state and flip the ^O character to the tty.  (The
old behavior has always set "sysrq_pressed" if ^O has been entered,
and it has not flipped the ^O character to the tty.)

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
Hendrik Brueckner 2008-12-16 00:09:38 +00:00 committed by Paul Mackerras
parent 532774ec7f
commit 368c1e3249

View file

@ -642,8 +642,11 @@ int hvc_poll(struct hvc_struct *hp)
/* Handle the SysRq Hack */
/* XXX should support a sequence */
if (buf[i] == '\x0f') { /* ^O */
sysrq_pressed = 1;
continue;
/* if ^O is pressed again, reset
* sysrq_pressed and flip ^O char */
sysrq_pressed = !sysrq_pressed;
if (sysrq_pressed)
continue;
} else if (sysrq_pressed) {
handle_sysrq(buf[i], tty);
sysrq_pressed = 0;