Messages in this thread | | | Date | Mon, 16 Jan 2012 19:54:27 +0000 | From | Alan Cox <> | Subject | Re: [git patches] libata updates for 3.3 |
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On Mon, 16 Jan 2012 11:47:12 -0800 Linus Torvalds <torvalds@linux-foundation.org> wrote:
> On Mon, Jan 16, 2012 at 11:42 AM, Alan Cox <alan@lxorguk.ukuu.org.uk> wrote: > > > > There are two sets of problems with that > > > > The first is that quite a few machines crap themselves if you do this > > because nobody has ever tested things like the IRQ routing or the > > firmware on suspend/resume when they find the hardwared controller has > > gone for a walk. > > I think this could trivially be solved at least on these kinds of > Apple machines by just making it a config option, and just not doing > it if it doesn't work. Some kernel command line to say "ahci=force" or > whatever.
There are patches for this from way back including a white list of devices that were tested
Just ping Matthew about
http://www.codon.org.uk/~mjg59/tmp/ahci_quirk_cleanup.diff
> That doesn't solve the "user never even realized" problem, but at > least it gives the user the possibility of solving the "crap firmware > doesn't even allow this".
For the "memory found over 4GB" case it may even be worth printing a warning.
> > Putting it back on suspend might help in some cases but then you get to > > pick your way through the documentation minefield, deal with device > > changes while in non AHCI mode, figure out how to set up registers the > > BIOS didn't etc. > > Yeah, no, that would just be horrible. I doubt it happens in practice, > though. I bet the normal PCI/AHCI resume will just do the right > thing. But I haven't tried..
Some BIOSes go off and try and re-unlock the drive with the bios password etc. They get most unhappy when the controller isn't in the mode they expected. Matthew used a white list for some he tested which didn't have problems. Most netbooks seem ok with it.
Alan
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