Re: 2.6.25-rc8-mm2: CONFIG_ATA_SFF: panic involving mount_block_root and down the road

[Jeff Garzik <jeff@garzik.org>]

Adrian Bunk wrote:
> On Sat, Apr 12, 2008 at 04:59:17AM +0400, Alexey Dobriyan wrote:
>> On Sat, Apr 12, 2008 at 03:43:45AM +0400, Alexey Dobriyan wrote:
>>> Pekka fixed SLUB for me, and now core2 box survives up and including to
>>> not finding / :
>>>
>>> Setup is SATA disk with plain old partitions, nothing lvmancy:
>>>
>>> 	/dev/sda2 on / type ext3 (rw,noatime)
>>>
>>> CONFIG_ATA=y
>>> CONFIG_ATA_ACPI=y
>>> CONFIG_SATA_AHCI=y
>>> CONFIG_ATA_PIIX=y
>>> CONFIG_PATA_JMICRON=y
>>>
>>> sda1 is for swap.
>>>
>>>
>>> [    3.920000] NET: Registered protocol family 1
>>> [    3.920000] VFS: Cannot open root device "sda2" or unknown-block(0,0)
>> The winner is partly me, partly git-libata-all.
>>
>> The latter introduced CONFIG_ATA_SFF option and put more or less every
>> SATA and PATA driver under it. The former honestly answered N to when
>> ATA_SFF popped up and failed to check existence of ATA_PIIX and
>> PATA_JMICRON in failing .config .
>>
>> Now raise hands those who knew that your ATA controller is SFF
>> compliant.
> 
> Is there any technical reason why we have to bother users with the 
> ATA_SFF option at all?
> 
> It sounds like a perfect canndidate for being select'ed.

'default y' is appropriate, but option that is used to disable a major 
swath of legacy code unneeded on modern FIS-based SATA platforms like AHCI.

	Jeff