> Matias, are you still there?  If so, can you please test the attached
> patch and see whether it fixes your problem - ie. boots okay without
> 'pci=nomsi'?
>
>   
> ------------------------------------------------------------------------
I've tried the patch and the kernel showsthe same behaviour. It does not 
work without the pci=nomsi parameter.

First, i tried with the 2.6.20.10 kernel and it did not work. Then i 
compile the kernel that i had when i start posting (2.6.20.4) but it was 
the same.

The sata controller mode in the BIOS has been always set to NATIVE-IDE.
The logs corresponding to the 2.6.20.4 has the bios controller mode set 
to AHCI. But... that doesn't matter, does it?

I simply patched the kernel, is there any option that i have to enable 
so the modifications take effect?

dmesg 2.6.20.10:
.....
[   36.376407] Kernel command line: 
root=UUID=5875415d-590b-47be-8e7c-30e4c073c6d2 ro
.....
[    5.743000] ahci 0000:00:12.0: AHCI 0001.0100 32 slots 4 ports 3 Gbps 
0xf impl SATA mode
[    5.744000] ahci 0000:00:12.0: flags: 64bit ncq ilck pm led clo pmp 
pio slum part
[    5.744000] ata1: SATA max UDMA/133 cmd 0xF883AD00 ctl 0x0 bmdma 0x0 
irq 222
[    5.744000] ata2: SATA max UDMA/133 cmd 0xF883AD80 ctl 0x0 bmdma 0x0 
irq 222
[    5.744000] ata3: SATA max UDMA/133 cmd 0xF883AE00 ctl 0x0 bmdma 0x0 
irq 222
[    5.744000] ata4: SATA max UDMA/133 cmd 0xF883AE80 ctl 0x0 bmdma 0x0 
irq 222
[    5.744000] scsi0 : ahci
[    5.744000] PM: Adding info for No Bus:host0
[    6.047000] ata1: SATA link down (SStatus 0 SControl 300)
[    6.047000] scsi1 : ahci
[    6.048000] PM: Adding info for No Bus:host1
[    6.506000] ata2: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
[   36.507000] ata2.00: qc timeout (cmd 0xec)
[   36.507000] ata2.00: failed to IDENTIFY (I/O error, err_mask=0x104)
[   37.313000] ata2: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
[   67.313000] ata2.00: qc timeout (cmd 0xec)
[   67.313000] ata2.00: failed to IDENTIFY (I/O error, err_mask=0x104)
[   68.119000] ata2: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
[   98.119000] ata2.00: qc timeout (cmd 0xec)
[   98.119000] ata2.00: failed to IDENTIFY (I/O error, err_mask=0x104)
[   98.925000] ata2: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
[   98.925000] scsi2 : ahci
[   98.925000] PM: Adding info for No Bus:host2
[   99.228000] ata3: SATA link down (SStatus 0 SControl 300)
[   99.228000] scsi3 : ahci
[   99.228000] PM: Adding info for No Bus:host3
[   99.531000] ata4: SATA link down (SStatus 0 SControl 300)

dmesg with 2.6.20.4
....
[   44.273845] Kernel command line: 
root=UUID=5875415d-590b-47be-8e7c-30e4c073c6d2 ro
....
[    6.864000] ata1: SATA link down (SStatus 0 SControl 300)
[    6.864000] scsi1 : ahci
[    6.864000] PM: Adding info for No Bus:host1
[    7.348000] ata2: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
[   37.348000] ata2.00: qc timeout (cmd 0xec)
[   37.348000] ata2.00: failed to IDENTIFY (I/O error, err_mask=0x104)
[   38.172000] ata2: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
[   68.172000] ata2.00: qc timeout (cmd 0xec)
[   68.172000] ata2.00: failed to IDENTIFY (I/O error, err_mask=0x104)
[   68.996000] ata2: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
[   98.996000] ata2.00: qc timeout (cmd 0xec)
[   98.996000] ata2.00: failed to IDENTIFY (I/O error, err_mask=0x104)
[   99.820000] ata2: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
[   99.820000] scsi2 : ahci
[   99.820000] PM: Adding info for No Bus:host2
[  100.132000] ata3: SATA link down (SStatus 0 SControl 300)
[  100.132000] scsi3 : ahci
[  100.132000] PM: Adding info for No Bus:host3
[  100.444000] ata4: SATA link down (SStatus 0 SControl 300)

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