2.6.19-git3 panics on boot - ata_piix/PCI related

["Alessandro Suardi" <alessandro.suardi@gmail.com>]

FC6-latest running on a Latitude D610, SATA hard disk;
 2.6.19 is okay, kernel built with oldconfig from the
 known-working setup fails to boot not recognizing the
 root partition, which is due to ata_piix not loading due
 to a PCI I/O reserve error.
Happens both with and without CONFIG_SYSFS_DEPRECATED
 (I first had it to N then thought it might have had something
 to do with the boot error so I rebuilt with Y - no change).

Messages hand-copied from the screen on the 2nd try:

Loading ata_piix.ko module
ata_piix 0000:00:1f.2: MAP [ P0 P2 IDE IDE ]
ACPI: PCI Interrupt 0000:00:1f.2[B] -> Link [LNKB] -> GSI 5 (level, low) -> IRQ5
PCI: Unable to reserve I/O region #1:8@1f0 for device 0000:00:1f.2
ata_piix: probe of 0000:00:1f.2 failed with error -16
[snip]
mount: could not find filesystem '/dev/root'


This is what is in the dmesg ring of 2.6.19:


ata_piix 0000:00:1f.2: version 2.00ac6
ata_piix 0000:00:1f.2: MAP [ P0 P2 IDE IDE ]
ACPI: PCI Interrupt 0000:00:1f.2[B] -> Link [LNKB] -> GSI 5 (level,
low) -> IRQ 5
PCI: Setting latency timer of device 0000:00:1f.2 to 64
ata1: SATA max UDMA/133 cmd 0x1F0 ctl 0x3F6 bmdma 0xBFA0 irq 14
ata2: PATA max UDMA/100 cmd 0x170 ctl 0x376 bmdma 0xBFA8 irq 15
scsi0 : ata_piix
ata1.00: ATA-6, max UDMA/100, 117210240 sectors: LBA
ata1.00: ata1: dev 0 multi count 8
ata1.00: applying bridge limits
ata1.00: configured for UDMA/100
scsi1 : ata_piix
ata2.00: ATAPI, max UDMA/33
ata2.00: configured for UDMA/33



--alessandro

"...when I get it, I _get_ it"

     (Lara Eidemiller)