Loading both the pata_atiixp and the ahci driver causes problems

Chuck Ebbert
2007-03-15T22:08:57Z

If you try to load both the pata_atiixp and the ahci driver
(for the same ATI SB600 adapter), very strange things happen.
The AHCI driver churns for three minutes or so, spewing
messages like this, then nothing works:

<6>ata3: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
<4>ata3.00: qc timeout (cmd 0xec)
<4>ata3.00: failed to IDENTIFY (I/O error, err_mask=0x104)

Shouldn't it be able to tell the device has already been
claimed by some other driver?

(This is kernel 2.6.21-rc, and it's almost certainly happening
in 2.6.20 as well.)