Most recent kernel where this bug did not occur:
Distribution: SuSE 10.0
Hardware Environment: SATA Drives on PDC20579 SATA II 150 and PDC20718 SATA 300 TX4
Software Environment:
Problem Description:
Kernel reports Oops when calling hddtemp an a SATA drive which is in standby mode.

Steps to reproduce:
hdparm -y /dev/sdx
hddtemp /dev/sdx

Jan 21 16:30:48 DatenGrab kernel: ata6: command timeout
Jan 21 16:30:48 DatenGrab kernel: ATA: abnormal status 0xFF on port 0xE029439C
Jan 21 16:30:48 DatenGrab kernel: ata6: translated ATA stat/err 0xff/00 to SCSI SK/ASC/ASCQ 0xb/
47/00
Jan 21 16:30:48 DatenGrab kernel: ata6: status=0xff { Busy }
Jan 21 16:30:48 DatenGrab kernel: ATA: abnormal status 0xFF on port 0xE029439C
Jan 21 16:30:48 DatenGrab kernel: ATA: abnormal status 0xFF on port 0xE029439C
Jan 21 16:30:48 DatenGrab kernel: ATA: abnormal status 0xFF on port 0xE029439C
Jan 21 16:30:48 DatenGrab kernel: ATA: abnormal status 0xFF on port 0xE029439C
Jan 21 16:30:51 DatenGrab kernel: ata6: unknown timeout, cmd 0xb0 stat 0xff
Jan 21 16:30:51 DatenGrab kernel: ata6: translated ATA stat/err 0xff/00 to SCSI SK/ASC/ASCQ 0xb/
47/00
Jan 21 16:30:51 DatenGrab kernel: ata6: status=0xff { Busy }
Jan 21 16:30:51 DatenGrab kernel: Assertion failed! qc != NULL,drivers/scsi/libata-
core.c,ata_pio_poll,line=2849
Jan 21 16:30:51 DatenGrab kernel: Assertion failed! qc != NULL,drivers/scsi/libata-
core.c,ata_pio_poll,line=2849
Jan 21 16:30:51 DatenGrab kernel: Assertion failed! qc != NULL,drivers/scsi/libata-
core.c,ata_pio_poll,line=2849
Jan 21 16:30:52 DatenGrab kernel: Assertion failed! qc != NULL,drivers/scsi/libata-
core.c,ata_pio_poll,line=2849
Jan 21 16:30:52 DatenGrab kernel: Assertion failed! qc != NULL,drivers/scsi/libata-
core.c,ata_pio_poll,line=2849
Jan 21 16:30:52 DatenGrab kernel: Assertion failed! qc != NULL,drivers/scsi/libata-
core.c,ata_pio_poll,line=2849
Jan 21 16:30:52 DatenGrab kernel: Assertion failed! qc != NULL,drivers/scsi/libata-
core.c,ata_pio_poll,line=2849
Jan 21 16:30:52 DatenGrab kernel: Assertion failed! qc != NULL,drivers/scsi/libata-
core.c,ata_pio_poll,line=2849
Jan 21 16:30:52 DatenGrab kernel: Assertion failed! qc != NULL,drivers/scsi/libata-
core.c,ata_pio_block,line=3274
Jan 21 16:30:52 DatenGrab kernel: Unable to handle kernel NULL pointer dereference at virtual address 
00000014
Jan 21 16:30:52 DatenGrab kernel:  printing eip:
Jan 21 16:30:52 DatenGrab kernel: e02b7ee3
Jan 21 16:30:52 DatenGrab kernel: *pde = 00000000
Jan 21 16:30:52 DatenGrab kernel: Oops: 0000 [#1]
Jan 21 16:30:52 DatenGrab kernel: Modules linked in: edd ipv6 nfsd w83627hf hwmon_vid hwmon 
eeprom i2c_isa button battery ac af_packet xfs exportfs reiserfs ohci1394 ieee1394 sk98lin i8xx_tco 
i2c_i801 intel_agp agpgart shpchp pci_hotplug i2c_core generic uhci_hcd raid5 xor parport_pc lp 
parport sata_promise libata dm_mod sg skge ohci_hcd ehci_hcd usb_storage usbcore fan thermal 
processor piix sd_mod scsi_mod ide_disk ide_core
Jan 21 16:30:52 DatenGrab kernel: CPU:    0
Jan 21 16:30:52 DatenGrab kernel: EIP:    0060:[<e02b7ee3>]    Not tainted VLI
Jan 21 16:30:52 DatenGrab kernel: EFLAGS: 00010246   (2.6.16-rc1-default)
Jan 21 16:30:52 DatenGrab kernel: EIP is at ata_pio_task+0xda/0x641 [libata]
Jan 21 16:30:52 DatenGrab kernel: eax: 00000053   ebx: 00000050   ecx: c0393600   edx: 00000050
Jan 21 16:30:52 DatenGrab kernel: esi: de422298   edi: 00000000   ebp: 00000010   esp: de3a7f34
Jan 21 16:30:52 DatenGrab kernel: ds: 007b   es: 007b   ss: 0068
Jan 21 16:30:52 DatenGrab kernel: Process ata/0 (pid: 2193, threadinfo=de3a6000 task=df0ad030)
Jan 21 16:30:52 DatenGrab kernel: Stack: <0>df6bfac0 decf3580 d8b3ddd4 c02a631b de3a7f88 
00000000 00000002 dece95c0
Jan 21 16:30:52 DatenGrab kernel:        00000000 de3a7f6c 00000002 df0ad158 de422848 dece95c0 
00000283 de422298
Jan 21 16:30:52 DatenGrab kernel:        c0122a60 e02b7e09 dece95c8 dece95c0 dece95d0 c0122b03 
c0122bde 00000001
Jan 21 16:30:52 DatenGrab kernel: Call Trace:
Jan 21 16:30:52 DatenGrab kernel:  [<c02a631b>] schedule+0x457/0x4c4
Jan 21 16:30:52 DatenGrab kernel:  [<c0122a60>] run_workqueue+0x64/0x93
Jan 21 16:30:52 DatenGrab kernel:  [<e02b7e09>] ata_pio_task+0x0/0x641 [libata]
Jan 21 16:30:52 DatenGrab kernel:  [<c0122b03>] worker_thread+0x0/0x10b
Jan 21 16:30:52 DatenGrab kernel:  [<c0122bde>] worker_thread+0xdb/0x10b
Jan 21 16:30:52 DatenGrab kernel:  [<c0114fe8>] default_wake_function+0x0/0xc
Jan 21 16:30:52 DatenGrab kernel:  [<c0124eef>] kthread+0x90/0xbc
Jan 21 16:30:52 DatenGrab kernel:  [<c0124e5f>] kthread+0x0/0xbc
Jan 21 16:30:52 DatenGrab kernel:  [<c0101005>] kernel_thread_helper+0x5/0xb
Jan 21 16:30:52 DatenGrab kernel: Code: 2b e0 68 4d cc 2b e0 68 69 cb 2b e0 e8 d6 ff e5 df 83 c4 14 
0f b6 d3 f6 c2 21 74 0c 83 8f 8c 00 00 00 02 e9 e7 01 00 00 8d 6f 10 <8a> 45 04 83 e8 05 3c 02 0f 
87 ca 01 00 00 80 e2 08 75 0f c7 86