I've marked a similar bug I've opened as a duplicate of this bug.
The bug is also relevant to X1600, the rest of the details including a test with upstream kernel are left on the original bug I've opened at: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/569597
I've marked a similar bug I've opened as a duplicate of this bug.
The bug is also relevant to X1600, the rest of the details including a test with upstream kernel are left on the original bug I've opened at: https:/ /bugs.launchpad .net/ubuntu/ +source/ linux/+ bug/569597