3.16-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Loic Poulain <loic.poul...@intel.com>

commit 4807b51895dce8aa650ebebc51fa4a795ed6b8b8 upstream.

In this expression: seq = (seq - 1) % 8
seq (u8) is implicitly converted to an int in the arithmetic operation.
So if seq value is 0, operation is ((0 - 1) % 8) => (-1 % 8) => -1.
The new seq value is 0xff which is an invalid ACK value, we expect 0x07.
It leads to frequent dropped ACK and retransmission.
Fix this by using '&' binary operator instead of '%'.

Signed-off-by: Loic Poulain <loic.poul...@intel.com>
Signed-off-by: Marcel Holtmann <mar...@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 drivers/bluetooth/hci_h5.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/bluetooth/hci_h5.c
+++ b/drivers/bluetooth/hci_h5.c
@@ -237,7 +237,7 @@ static void h5_pkt_cull(struct h5 *h5)
                        break;
 
                to_remove--;
-               seq = (seq - 1) % 8;
+               seq = (seq - 1) & 0x07;
        }
 
        if (seq != h5->rx_ack)


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to