Comment 126 for bug 1521173

For every one affected, at least attach the output of `lspci -nn`, `dmesg`, and give details for your system.

As this bug has gotten long, and causes go from firmware, firmware configuration to hardware issues, it’s better if you opened a separate report directly upstream, after testing the current Linux kernel using Ubuntu PPA repository [1].

[1]: https://kernel.ubuntu.com/~kernel-ppa/