Hi, I've got a UDMA66 drive on a HPT370 controller. Whenever I issue a command to switch to a higher DMA mode ("hdparm -X67" or "-X68") the machine locks completely - no response to Magic SysRq at all. The drive starts in udma2 upon bootup (it's a "Nikimi NIK-XL300A", not a brand I've seen before). I've not tried it with other devices on this controller, but a Maxtor 53073H6 starts straight in udma5, so I tend not to want to switch it down to a lower DMA mode. This happens on 2.4.0-test9, and -test10-pre4, although I suspect it's happened on others too. -- Rob [EMAIL PROTECTED] - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/