Re: [gentoo-user] AHCI/IDE-question

[meino.cramer@gmx.de]

Volker Armin Hemmann <volkerarmin@googlemail.com> [11-01-22 03:04]:
> On Friday 21 January 2011 21:05:30 meino.cramer@gmx.de wrote:
> > Mark Knecht <markknecht@gmail.com> [11-01-21 20:36]:
> > > On Fri, Jan 21, 2011 at 11:16 AM, Volker Armin Hemmann
> > > <volkerarmin@googlemail.com> wrote:
> > > <SNIP>
> > > 
> > > >>    I'm happy to be corrected (by Volker I'm sure) but that's my
> > > >> guess
> > > >> as to what you're seeing.
> > > > 
> > > > you are confusing bios calls and bios programming chips as.... also
> > > > - is there any good reason to use IDE mode? Any? At all?
> > > 
> > > I don't believe I'm 'confusing bios calls with bios programming'. The
> > > BIOS can do whatever it wants to in programming the chips as long as
> > > grub can still find the kernel. After grub finds the kernel the kernel
> > > is free to override whatever chip programming the BIOS has done and
> > > reprogram the chips as it sees best.
> > > 
> > > I think the issue meino possibly has is that he likely didn't include
> > > an Int13 type driver in the kernel or most likely his system would
> > > have booted like it did in the _very_ old days.
> > > 
> > > I agree that there isn't any good reason I know of to use IDE mode
> > > unless the other modes the BIOS provides don't work.
> > > 
> > > I cannot get into my Asus BIOS at the moment, but as I remember it
> > > Asus gave me something like
> > > 
> > > IDE
> > > AHCI
> > > AHCI + compatibility
> > > 
> > > IIRC I had to use the last one to get mine to boot but I may be wrong
> > > about that. I only mention this as meino is also using Asus so he
> > > might look for similar options.
> > > 
> > > - Mark
> > 
> > Hi,
> > 
> > I switched the BIOS from IDE (kernel is using AHCI) to AHCI (kernel
> > uses AHCI). The dmesg says (I did a dmesg | grep -i ahci now, previous
> > check was done with dmesg | grep AHCI only):
> > 
> >     solfire:/root>dmesg | grep -i ahci
> >     ahci 0000:00:11.0: version 3.0
> > *0* ahci 0000:00:11.0: PCI INT A -> GSI 19 (level, low) -> IRQ 19
> > *1* ahci 0000:00:11.0: irq 78 for MSI/MSI-X
> > *2* ahci 0000:00:11.0: AHCI 0001.0200 32 slots 6 ports 3 Gbps 0x3f impl SATA
> > mode *3* ahci 0000:00:11.0: flags: 64bit ncq sntf ilck pm led clo pmp pio
> > slum part scsi0 : ahci
> >     scsi1 : ahci
> >     scsi2 : ahci
> >     scsi3 : ahci
> >     scsi4 : ahci
> >     scsi5 : ahci
> >     ahci 0000:07:00.0: PCI INT A -> GSI 44 (level, low) -> IRQ 44
> > *4* ahci 0000:07:00.0: AHCI 0001.0000 32 slots 2 ports 3 Gbps 0x3 impl SATA
> > mode *5* ahci 0000:07:00.0: flags: 64bit ncq pm led clo pmp pio slum part
> > *6* ahci 0000:07:00.0: setting latency timer to 64
> >     scsi6 : ahci
> >     scsi7 : ahci
> > 
> > For me bare eye this looks like the kernel ha switched all seven ports
> > to AHCI. Lines marked with "*n*" are still a riddle to me. May be
> > Volker will give us some enlightment?
> > Why is line *1* of the first block missing in the second block,
> > Volker? Why is line *2* talking about "0x3f" while line  *4* is using
> > "0x3", Volker? Why differ line *5* from line *3*, Volker? What does
> > all these flags mean?
> > 
> 
> you know - there are websites for that. Google is your friend. But even a 
> glance would reveal to you:
> two different chips.
> One using MSI for interrupts the second not.
> 
> > I find this interesting:
> > 
> > http://www.linuxquestions.org/questions/linux-hardware-18/6-tips-for-improvi
> > ng-hard-drive-performance-835034/
> 
> it is a start. But the first link there... just saying.. there is no magically 
> correct value for stride or chunk.
> 
> Oh and if you are using AFT drives make sure the partitions are set up 
> correctly.
> 
> Also:
> https://ata.wiki.kernel.org/index.php/Main_Page
> 

Hi Volker,

I have done the partition alignment thingy when I installed my disk a
year ago (or so). Thanks for the hint anyway... :)

If you know a webite, which explains all that low level stuff like the
flags I mentioned I would be happy, if would be so kind to post the 
link here.

Thanks a lot for your help in advance!
Best regards,
mcc