On 13/12/16 21:42, peter green wrote:
OK, I found that adding ahci-imx.hotplug=1 to the kernel command line made it work.I would guess at this point either a race condition or a power glitch (maybe powering the HDD off one of the USB ports wasn't such a good idea).
Checking the schematic I notice that the USB ports seem to have power control, I wonder if they are power-cycled at some point during the boot process.