Lars Michael Jogback wrote:
>> Can you please try the attached patch and see whether anything is
>> different?
> 
> Yes, it made it working.

Heh... Okay, that's unexpected.

> You don't think it has something todo with the spin-up time?
> 
> The spin-up time on these disks is quite long:
> smartctl -a /dev/sdn | grep Spin_Up_Time
>   3 Spin_Up_Time            0x0007   068   068   011    Pre-fail  Always       -       10240

Maybe but I don't know.  Spin up is usually waited upon by device
readiness wait after SRST which libata does every time it probes or
resets a device behind PMP.  The drive is bringing link down briefly
after SRST is complete.  It doesn't make much sense.  Maybe some
quirkiness in the firmware?

Can you please try the attached patch?  If it doesn't work, please
increment the constant 200LU by 100 each time and find out where it
starts to work.

Thanks.

-- 
tejun