Hello all.
I did some tests of how suspend works.
menuconfig: default +ASRock +E350M1 +Use VGA BIOS payload: SeaBIOS system: Windows 8 and Trisquel 6.0 dual-boot with GRUB2 snapshot: cb891de
At first there is mess with common terms used for low power modes do describe it correct. I'd prefer to use OS neutral terms for it but only source i have is [1] which do not provide much. I see there Sleep=Suspend for mode, when power is lowered to wake up fast but necessary to do it successfull; Hibernate for dumping memory to disk and complete power off; and some Hybrid mode looks like mix of both.
In short, my tests say with Win8 suspend works and with Trisquel6 not. Below are more details.
Win8: Sleep button is available, but pressing it seems actually activate Hybrid mode. Computer looks completely powered off (with vendor BIOS power led was blinking). By pressing power button computer resumes from POST but power to USB devices is not restored (mouse do not lit). So computer wakes up with no keyboard working and in GRUB i cannot select to boot Win8. (If leave GRUB to boot Trisquel nor mouse nor keyboard are working.) If to unplug power during low power mode (or power off by holding power button 4 secounds before it boots and power on again) USB power is restored. I can select to boot Win8. System wakes up in same state it was left.
Trisquel6. Suspend button is available. I am not sure what low power mode is activated by pressing but computer looks completely powered off. With pressing power button same issue with USB devices in GRUB, but during boot they got reinitialised (as system boots fresh) and work ok. AFAIK when resume with linux happen GRUB sees it and do not show OS menu but doing resume. So may be issue with resume not working in linux is with BIOS-GRUB communication.
Hope my information can somehow help.
Cheers!