I have a similar immediate wakeup issue:

[ 7951.156318] PM: Syncing filesystems ... done.
[ 7951.170491] PM: Preparing system for mem sleep
[ 7951.186366] Freezing user space processes ... (elapsed 0.01 seconds) done.
[ 7951.200152] Freezing remaining freezable tasks ... (elapsed 0.01 seconds) done.
[ 7951.216109] PM: Entering mem sleep
[ 7951.216130] Suspending console(s) (use no_console_suspend to debug)
[ 7951.216677] sd 0:0:0:0: [sda] Stopping disk
[ 7951.216854] ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x0
[ 7951.216857] ata1.00: failed command: STANDBY IMMEDIATE
[ 7951.216864] ata1.00: cmd e0/00:00:00:00:00/00:00:00:00:00/a0 tag 0
[ 7951.216864]          res 51/04:00:00:00:00/00:00:00:00:00/a0 Emask 0x1 (device error)
[ 7951.216865] ata1.00: status: { DRDY ERR }
[ 7951.216867] ata1.00: error: { ABRT }
[ 7951.216876] ata1.00: device reported invalid CHS sector 0
[ 7951.216894] sd 0:0:0:0: [sda] START_STOP FAILED
[ 7951.216896] sd 0:0:0:0: [sda]  
[ 7951.216897] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
[ 7951.216899] sd 0:0:0:0: [sda]  
[ 7951.216900] Sense Key : Aborted Command [current] [descriptor]
[ 7951.216903] sd 0:0:0:0: [sda]  
[ 7951.216905] Add. Sense: No additional sense information
[ 7951.216916] dpm_run_callback(): scsi_bus_suspend+0x0/0x20 returns 134217730
[ 7951.216920] PM: Device 0:0:0:0 failed to suspend: error 134217730
[ 7951.216921] PM: Some devices failed to suspend
[ 7951.476689] PM: resume of devices complete after 259.763 msecs
[ 7951.476831] PM: resume devices took 0.260 seconds
[ 7951.476884] PM: Finishing wakeup.


This is an old old Compaq V2000 with IDE.  I an using an IDE to SD converter to have a "flash drive" of sorts.  (slow, but stable!)

Relevant ATA startup.  I am running the OS from what it thinks is a "removable" disk.

[    2.062741] scsi0 : pata_atiixp
[    2.066210] scsi1 : pata_atiixp
[    2.067047] ata1: PATA max UDMA/100 cmd 0x1f0 ctl 0x3f6 bmdma 0x8410 irq 14
[    2.067050] ata2: PATA max UDMA/100 cmd 0x170 ctl 0x376 bmdma 0x8418 irq 15
[    2.096151] ssb: Found chip with id 0x4318, rev 0x02 and package 0x02
[    2.096166] ssb: Core 0 found: ChipCommon (cc 0x800, rev 0x0D, vendor 0x4243)
[    2.096176] ssb: Core 1 found: IEEE 802.11 (cc 0x812, rev 0x09, vendor 0x4243)
[    2.096185] ssb: Core 2 found: PCI (cc 0x804, rev 0x0C, vendor 0x4243)
[    2.096195] ssb: Core 3 found: PCMCIA (cc 0x80D, rev 0x07, vendor 0x4243)
[    2.136166] ssb: Sonics Silicon Backplane found on PCI device 0000:05:02.0
[    2.229220] ata2.00: ATAPI: HL-DT-STCD-RW/DVD DRIVE GCC-4244N, 1.02, max MWDMA2
[    2.229325] ata1.00: CFA: Memory Card Adapter, 67281306, max UDMA/66
[    2.229328] ata1.00: 63272960 sectors, multi 0: LBA
[    2.229333] ata1.00: limited to UDMA/33 due to 40-wire cable
[    2.236726] ata1.00: configured for UDMA/33
[    2.236875] scsi 0:0:0:0: Direct-Access     ATA      Memory Card Adap 6728 PQ: 0 ANSI: 5
[    2.237165] sd 0:0:0:0: [sda] 63272960 512-byte logical blocks: (32.3 GB/30.1 GiB)
[    2.237216] sd 0:0:0:0: [sda] Write Protect is off
[    2.237220] sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00
[    2.237244] sd 0:0:0:0: [sda] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
[    2.237361] sd 0:0:0:0: Attached scsi generic sg0 type 0
[    2.241462]  sda: sda1 sda2 < sda5 sda6 >
[    2.241899] sd 0:0:0:0: [sda] Attached SCSI removable disk