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Input: keyboard - add locking around event handling

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Keyboard input handler is multiplexing events form all keyboard-like
devices in the system. Because of that per-device lock provided by
input core is not enough to prevent clashes in ked_event() and we
need our own lock to ensure that only one thread at a time executing
kbd_event().

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This commit is contained in:
Dmitry Torokhov 2009-11-29 23:40:58 -08:00
parent dbe1420b4b
commit 21cea58e49
1 changed files with 7 additions and 0 deletions
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7
drivers/char/keyboard.c
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@ -132,6 +132,7 @@ int shift_state = 0;
*/ */
static struct input_handler kbd_handler; static struct input_handler kbd_handler;
static DEFINE_SPINLOCK(kbd_event_lock);
static unsigned long key_down[BITS_TO_LONGS(KEY_CNT)]; /* keyboard key bitmap */ static unsigned long key_down[BITS_TO_LONGS(KEY_CNT)]; /* keyboard key bitmap */
static unsigned char shift_down[NR_SHIFT]; /* shift state counters.. */ static unsigned char shift_down[NR_SHIFT]; /* shift state counters.. */
static int dead_key_next; static int dead_key_next;
@ -1296,10 +1297,16 @@ static void kbd_keycode(unsigned int keycode, int down, int hw_raw)
static void kbd_event(struct input_handle *handle, unsigned int event_type, static void kbd_event(struct input_handle *handle, unsigned int event_type,
unsigned int event_code, int value) unsigned int event_code, int value)
{ {
/* We are called with interrupts disabled, just take the lock */
spin_lock(&kbd_event_lock);
if (event_type == EV_MSC && event_code == MSC_RAW && HW_RAW(handle->dev)) if (event_type == EV_MSC && event_code == MSC_RAW && HW_RAW(handle->dev))
kbd_rawcode(value); kbd_rawcode(value);
if (event_type == EV_KEY) if (event_type == EV_KEY)
kbd_keycode(event_code, value, HW_RAW(handle->dev)); kbd_keycode(event_code, value, HW_RAW(handle->dev));
spin_unlock(&kbd_event_lock);
tasklet_schedule(&keyboard_tasklet); tasklet_schedule(&keyboard_tasklet);
do_poke_blanked_console = 1; do_poke_blanked_console = 1;
schedule_console_callback(); schedule_console_callback();