Hi Andrey,
On Wed, Sep 18, 2013 at 04:35:56PM +0400, Andrey Moiseev wrote:
> When 8042 internal data buffer is full, the driver
> erroneously decides that the controller is not present.
>
> I've already sent this 2 weeks ago, but that message received no comments.
>
Sorry about the delay. How about we rework it a bit and make flush
return success/error instead of number of bytes read, like in the patch
below?
Thanks.
--
Dmitry
Input: i8042 - i8042_flush fix for a full 8042 buffer
From: Andrey Moiseev <o2g.org.ru@xxxxxxxxx>
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@xxxxxxxxx>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
---
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 78e4de4..52c9ebf 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;
}
--
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