From: Fredrik Roubert Date: Mon, 26 Jun 2006 07:24:35 +0000 (-0700) Subject: [PATCH] fix magic sysrq on strange keyboards X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=d2be8ee53856c3c510d4d38f534979747db65d96;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git [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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/char/keyboard.c b/drivers/char/keyboard.c index edd996f6fb87..13e3126c1de5 100644 --- a/drivers/char/keyboard.c +++ b/drivers/char/keyboard.c @@ -151,6 +151,7 @@ unsigned char kbd_sysrq_xlate[KEY_MAX + 1] = "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 @@ static void kbd_keycode(unsigned int keycode, int down, 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 @@ static void kbd_keycode(unsigned int keycode, int down, #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;