Comment 21 for bug 1701081

I tested this for a while to be sure of the results. It appears that with the mainline kernel 4.13.0-041300rc1-generic resuming from hibernate works perfectly without the need to add the "acpi_osi=Linux" kernel boot parameter. It worked correctly and reliably 100% of the times I tried it (even repeatedly without a full shutdown).

Instead, even with the (almost) latest 4.2.0-83 Ubuntu kernel, more often than not resuming from hibernate produces a blank screen after unlocking the hard disk (for dm-crypt), unless the "acpi_osi=Linux" kernel boot parameter is used. I must also say that, in any case (even with such added parameter), sometimes resuming is not 100% reliable because some devices seems not to wake up correctly (it happened with keyboard or touchpad in my case, a couple of times).