[PATCH] fix magic sysrq on strange keyboards
Magic sysrq fails to work on many keyboards, particulary most of notebook
keyboards. This patch fixes it.
The idea is quite simple: Discard the SysRq break code if Alt is still being
held down. This way the broken keyboard can send the break code (or the user
with a normal keyboard can release the SysRq key) and the kernel waits until
the next key is pressed or the Alt key is released.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/char/keyboard.c b/drivers/char/keyboard.c
index edd996f..13e3126 100644
--- a/drivers/char/keyboard.c
+++ b/drivers/char/keyboard.c
@@ -151,6 +151,7 @@
"230\177\000\000\213\214\000\000\000\000\000\000\000\000\000\000" /* 0x50 - 0x5f */
"\r\000/"; /* 0x60 - 0x6f */
static int sysrq_down;
+static int sysrq_alt_use;
#endif
static int sysrq_alt;
@@ -1143,7 +1144,7 @@
kbd = kbd_table + fg_console;
if (keycode == KEY_LEFTALT || keycode == KEY_RIGHTALT)
- sysrq_alt = down;
+ sysrq_alt = down ? keycode : 0;
#ifdef CONFIG_SPARC
if (keycode == KEY_STOP)
sparc_l1_a_state = down;
@@ -1163,9 +1164,14 @@
#ifdef CONFIG_MAGIC_SYSRQ /* Handle the SysRq Hack */
if (keycode == KEY_SYSRQ && (sysrq_down || (down == 1 && sysrq_alt))) {
- sysrq_down = down;
+ if (!sysrq_down) {
+ sysrq_down = down;
+ sysrq_alt_use = sysrq_alt;
+ }
return;
}
+ if (sysrq_down && !down && keycode == sysrq_alt_use)
+ sysrq_down = 0;
if (sysrq_down && down && !rep) {
handle_sysrq(kbd_sysrq_xlate[keycode], regs, tty);
return;