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| author | Andrey Moiseev <o2g.org.ru@gmail.com> | 2013-09-17 00:17:31 +0200 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2013-09-18 21:22:06 +0200 |
| commit | 2f0d2604134880f739642fd7c3ae55db33c838e7 (patch) | |
| tree | 8bde47595130fca3526efb343e2f3a2ed9b6901c /drivers/input | |
| parent | Input: pxa27x_keypad - fix NULL pointer dereference (diff) | |
| download | linux-2f0d2604134880f739642fd7c3ae55db33c838e7.tar.xz linux-2f0d2604134880f739642fd7c3ae55db33c838e7.zip | |
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 <o2g.org.ru@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Diffstat (limited to 'drivers/input')
| -rw-r--r-- | drivers/input/serio/i8042.c | 23 |
1 files 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; } |