On Mon, 16 Jan 2012 11:47:12 -0800 Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > On Mon, Jan 16, 2012 at 11:42 AM, Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> 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 -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
