False:
2.6.0 - 2.6.19: libata guarantees that all PCI BARs are reserved to the
libata driver.
2.6.20: no guarantee that all PCI BARs are reserved to libata driver.
Real-life ata_piix example already provided, where a PCI BAR is no
longer reserved to the driver.
2.6.21 - infinity: libata guarantees that all PCI BARs are reserved to
the driver.
Jeff
-