From 2f0d2604134880f739642fd7c3ae55db33c838e7 Mon Sep 17 00:00:00 2001 From: Andrey Moiseev Date: Mon, 16 Sep 2013 15:17:31 -0700 Subject: [PATCH] Input: i8042 - i8042_flush fix for a full 8042 buffer When 8042 internal data buffer is full, the driver erroneously decides that the controller is not present. i8042_flush returns the number of flushed bytes, which is in 0 - I8042_BUFFER_SIZE range inclusive. Therefore, i8042_flush has no way to indicate an error. Moreover i8042_controller_check takes initially full buffer (i8042_flush returned I8042_BUFFER_SIZE) as a sign of absence of the controller. Let's change i8042 to return success/error instead and make sure we do not return error prematurely. Signed-off-by: Andrey Moiseev Signed-off-by: Dmitry Torokhov --- drivers/input/serio/i8042.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c index 78e4de42efaa..52c9ebf94729 100644 --- a/drivers/input/serio/i8042.c +++ b/drivers/input/serio/i8042.c @@ -223,21 +223,26 @@ static int i8042_flush(void) { unsigned long flags; unsigned char data, str; - int i = 0; + int count = 0; + int retval = 0; spin_lock_irqsave(&i8042_lock, flags); - while (((str = i8042_read_status()) & I8042_STR_OBF) && (i < I8042_BUFFER_SIZE)) { - udelay(50); - data = i8042_read_data(); - i++; - dbg("%02x <- i8042 (flush, %s)\n", - data, str & I8042_STR_AUXDATA ? "aux" : "kbd"); + while ((str = i8042_read_status()) & I8042_STR_OBF) { + if (count++ < I8042_BUFFER_SIZE) { + udelay(50); + data = i8042_read_data(); + dbg("%02x <- i8042 (flush, %s)\n", + data, str & I8042_STR_AUXDATA ? "aux" : "kbd"); + } else { + retval = -EIO; + break; + } } spin_unlock_irqrestore(&i8042_lock, flags); - return i; + return retval; } /* @@ -849,7 +854,7 @@ static int __init i8042_check_aux(void) static int i8042_controller_check(void) { - if (i8042_flush() == I8042_BUFFER_SIZE) { + if (i8042_flush()) { pr_err("No controller found\n"); return -ENODEV; }