Comment 33 for bug 209454

I started to have this problem with the upgrade to Ubuntu 8.04 (64bit) on a ASUS A8V-MX motherboard ( VT8251 SATA controller in ahci mode). Still present in 9.04 with kernel 2.6.28-16. Last kernel that works for me (even now in 9.04) is 2.6.22-16 so I intend to keep it till this problem is solved. I believe it is not a hardware problem since every kernel from Ubuntu 6.10 up to the 7.10 has worked for me. My suggestion is to look around the ahci module code.
The few lines I could write down before it drops to busybox shell look very similar with what was posted prior to me:
  ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
  ata1.00: qc timeout (cmd 0xec)
  ata1.00: failed to IDENTIFY (I/O error, err_mask=0x4)
I could not save more from dmesg since not even my floppy can be mounted at the busybox prompt (shows "invalid arguments" with an ext2 formatted floppy disk). The busybox "more" does not work either so I could not look too close into the dmesg output.
For reference this is what the "good" kernel shows when it works:
===========normal boot ahci section================
[ 28.709134] scsi0 : ahci
[ 28.709390] scsi1 : ahci
[ 28.709543] scsi2 : ahci
[ 28.709695] scsi3 : ahci
[ 28.710323] ata1: SATA max UDMA/133 cmd 0xffffc200001a2d00 ctl 0x0000000000000000 bmdma 0x0000000000000000 irq
 21
[ 28.710328] ata2: SATA max UDMA/133 cmd 0xffffc200001a2d80 ctl 0x0000000000000000 bmdma 0x0000000000000000 irq
 21
[ 28.710332] ata3: SATA max UDMA/133 cmd 0xffffc200001a2e00 ctl 0x0000000000000000 bmdma 0x0000000000000000 irq
 21
[ 28.710337] ata4: SATA max UDMA/133 cmd 0xffffc200001a2e80 ctl 0x0000000000000000 bmdma 0x0000000000000000 irq
 21
[ 29.195349] ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
[ 29.196212] ata1.00: ATA-7: ST3300831AS, 3.03, max UDMA/133
[ 29.196215] ata1.00: 586072368 sectors, multi 16: LBA48 NCQ (depth 0/32)
[ 29.197082] ata1.00: configured for UDMA/133
[ 29.510744] ata2: SATA link down (SStatus 0 SControl 300)
[ 29.822153] ata3: SATA link down (SStatus 0 SControl 300)
[ 30.133562] ata4: SATA link down (SStatus 0 SControl 300)
===========================================================
A bit dissapointing that this kind of critical failure in my opinion introduced some time ago can stay around for so long.