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>
diff --git a/drivers/char/hvc_console.c b/drivers/char/hvc_console.c
index 74ecb5b..fb57f67 100644
--- a/drivers/char/hvc_console.c
+++ b/drivers/char/hvc_console.c
@@ -642,8 +642,11 @@
/* 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;