This sounds much like bug #745112 although the chipset is different.
Install and boot this kernel, and see if it fixes it: http://kernel.ubuntu.com/~kernel-ppa/mainline/drm-intel-next-proposed/
If so, then install this kernel and see if it also fixes it or not: http://people.canonical.com/~acelan/bugs/lp753189/
If it does, then that'll narrow down what patch the kernel team needs to pull.
This sounds much like bug #745112 although the chipset is different.
Install and boot this kernel, and see if it fixes it: kernel. ubuntu. com/~kernel- ppa/mainline/ drm-intel- next-proposed/
http://
If so, then install this kernel and see if it also fixes it or not: people. canonical. com/~acelan/ bugs/lp753189/
http://
If it does, then that'll narrow down what patch the kernel team needs to pull.