I recently ran into a weird issue on one of my systems (running Ubuntu MATE 18.04 with both stock and HWE kernels):
When I connect any device to SATA ports 5 or 6, I get errors like this on boot:
Apr 28 18:29:21.454814 ubuntubox kernel: ACPI BIOS Error (bug): Could not resolve [\_SB.PCI0.SAT0.SPT5._GTF.DSSP], AE_NOT_FOUND (20180531/psargs-330)
Apr 28 18:29:21.454822 ubuntubox kernel: No Local Variables are initialized for Method [_GTF]
Apr 28 18:29:21.454829 ubuntubox kernel: No Arguments are initialized for method [_GTF]
Apr 28 18:29:21.454836 ubuntubox kernel: ACPI Error: Method parse/execution failed \_SB.PCI0.SAT0.SPT5._GTF, AE_NOT_FOUND (20180531/psparse-516)
I do not see any other negative effect, except for the error messages so far, but when I connect the same device to one of the first four SATA ports those messages disappear entirely.
I tried several different devices and the result is always the same.
According to the manual of the mainboard (MSI H87-G41 PC Mate) all 6 SATA ports are supposed to be of the same type and connected to the same Intel H87 controller.
The BIOS is the latest version available (3.9).
Any idea what's going on here?