The SSD of model SSDSA1NW160G3 1.8" causes a consistent 30 second delay when present in a ThinkPad X301 with Libreboot. This delay does not occur under the factory BIOS.
With the SeaBIOS payload, it hangs for this time after the SeaBIOS version and Device UUID show.
With the GRUB payload, the screen is blank the whole time.
After the delay, the payload executes as normal. Boot works fine in SeaBIOS (standalone or chainloaded from GRUB), or in GRUB when chainloaded from SeaBIOS. In GRUB-only setups it iterates through the "attempting to load [...] devices" and fails back to the GRUB menu.
The contents of the drive do not seem to matter. The delay is the same whether an OS is present or the whole drive has been zeroed/urandomed.
Tested across the following revisions:
Tested across four X301 laptops, with all other bootable devices removed. Three SSDs of this model were tested, with consistent results. All appear to have the latest vendor firmware. The delay has not been seen on other SSDs (presently I only have Samsung ones as a control).
Well coreboot master with SeaBIOS gives me the same problem. I suppose I should take this upstream and run some more tests with more logging.