I've traced the reason for the spin-up to the disk_smart_read_thresholds() call at the end of sk_disk_open() in atasmart.c.
Apparently the SMART "Read Thresholds" command implies spinning up the disk, at least on my and Ricardo's controllers. I wonder why libatasmart4 always executes that call already when opening the disk device.
I've traced the reason for the spin-up to the disk_smart_ read_thresholds () call at the end of sk_disk_open() in atasmart.c.
Apparently the SMART "Read Thresholds" command implies spinning up the disk, at least on my and Ricardo's controllers. I wonder why libatasmart4 always executes that call already when opening the disk device.