Disabling SATA Link Power Management (LPM) in GRUB

[Marc Giger <gigerstyle@gmx.ch>]

Dear Kernel Devs,

I spent my Samsung RF511 Notebook a OCZ Vertex III SSD. Unfortunately
there seems to be an incompatibility between these. Samsung is not
willing to help me, because they won't support foreign Hard- (OCZ SSD)
and Software (Linux).

I've found the following forum entries which I think is the problem.
 
http://www.ocztechnologyforum.com/forum/showthread.php?88340-Vertex-3-Windows-install-in-AHCI-mode-on-Intel-6-series-Chipset-platforms

http://www.ocztechnologyforum.com/forum/showthread.php?88630-Vertex-3-problem-booting-windows-7-with-HM65-Sandybride-chips-%28Laptops%29/page3

It seems because of this GRUB has problem loading the stages from the
disk in my case.

So my question are:

1. Does this make sense to you? Is it possible that it could be the
reason?
2. Can the problem be solved when I implement a hack into GRUB to
disable the LPM before the stages are loaded from disk?
3. What are the implementation steps which must be done? When I
understand the code in the kernel correctly, the registers are
written over memory mapped areas. Can it be done without mmio?

Thanks a lot!

Kind Regards

Marc


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