I tried word 78 bit 5(Hardware Feature Control) which does not work,
it is 0 on my HDD sample with log 30h page 08h and DevSlp supported.

Seems that word 78 bit 5 is only the sufficient condition, not the
essential condition. Do you guys have suggestion?

Eventually I received the confirmation from the DevSlp HDD vendor,
bit 5 should be and will be set in production drives with log 30h
page 08h supported. So I will submit a patch to use it instead.


Hi Jeff,

I don't know when I will receive some production drives to verify
my patch, are you okay if I submit my patch first without testing
so as to meet kernel 3.7 bug fix window?

Thanks,
Shane