Ralf Müller wrote:

The kernel oops reported for 2.6.15-rc7 when calling hddtemp on a sata
drive which is in standby mode is still present in 2.6.15. Maybe someone
is interested.

Regards
Ralf

Hi Ralf,

It looks like the command is running in PIO polling thread.
The timeout handler is called and the qc is cleared.
So, the PIO polling thread got NULL qc.

Could you post more trace before the timeout occurs, thanks,

Albert

Jan  3 15:21:35 DatenGrab kernel: ata1: unknown timeout, cmd 0xb0 stat 0xff
Jan  3 15:21:35 DatenGrab kernel: ata1: translated ATA stat/err 0xff/00
to SCSI SK/ASC/ASCQ 0xb/47/00
Jan  3 15:21:35 DatenGrab kernel: ata1: status=0xff { Busy }
Jan  3 15:21:35 DatenGrab kernel: Assertion failed! qc !=
NULL,drivers/scsi/libata-core.c,ata_pio_block,line=3216
Jan  3 15:21:35 DatenGrab kernel: Unable to handle kernel NULL pointer
dereference at virtual address 00000014
Jan  3 15:21:35 DatenGrab kernel:  printing eip:
Jan  3 15:21:35 DatenGrab kernel: e02d9a3e
Jan  3 15:21:35 DatenGrab kernel: *pde = 00000000
Jan  3 15:21:35 DatenGrab kernel: Oops: 0000 [#1]
Jan  3 15:21:35 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 i2c_i801 i2c_core generic
i8xx_tco shpchp pci_hotplug uhci_hcd intel_agp agpgart 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  3 15:21:35 DatenGrab kernel: CPU:    0
Jan  3 15:21:35 DatenGrab kernel: EIP:    0060:[<e02d9a3e>]    Not
tainted VLI
Jan  3 15:21:35 DatenGrab kernel: EFLAGS: 00010292   (2.6.15-default)
Jan  3 15:21:35 DatenGrab kernel: EIP is at ata_pio_block+0xb9/0xfd
[libata]
Jan  3 15:21:35 DatenGrab kernel: eax: 00000056   ebx: c14d6284   ecx:
00000000   edx: 00000000
Jan  3 15:21:35 DatenGrab kernel: esi: 55b17c50   edi: 00000000   ebp:
c14d6284   esp: def3df70
Jan  3 15:21:35 DatenGrab kernel: ds: 007b   es: 007b   ss: 0068
Jan  3 15:21:35 DatenGrab kernel: Process ata/0 (pid: 2179,
threadinfo=def3c000 task=deefc580)
Jan  3 15:21:35 DatenGrab kernel: Stack: c14d6284 deefb3c0 00000287
e02d9b00 c14d683c c01230b6 e02d9ae3 00000001
Jan  3 15:21:35 DatenGrab kernel:        00000000 00000000 00010000
00000000 00000000 deefc580 c01150bc 00100100
Jan  3 15:21:35 DatenGrab kernel:        00200200 ffffffff ffffffff
def3c000 de189f54 deefb3c0 c0122f77 c0125c9f
Jan  3 15:21:35 DatenGrab kernel: Call Trace:
Jan  3 15:21:35 DatenGrab kernel:  [<e02d9b00>] ata_pio_task+0x1d/0x54
[libata]
Jan  3 15:21:35 DatenGrab kernel:  [<c01230b6>] worker_thread+0x13f/0x19d
Jan  3 15:21:35 DatenGrab kernel:  [<e02d9ae3>] ata_pio_task+0x0/0x54
[libata]
Jan  3 15:21:35 DatenGrab kernel:  [<c01150bc>]
default_wake_function+0x0/0xc
Jan  3 15:21:35 DatenGrab kernel:  [<c0122f77>] worker_thread+0x0/0x19d
Jan  3 15:21:35 DatenGrab kernel:  [<c0125c9f>] kthread+0x63/0x8f
Jan  3 15:21:35 DatenGrab kernel:  [<c0125c3c>] kthread+0x0/0x8f
Jan  3 15:21:35 DatenGrab kernel:  [<c0101281>]
kernel_thread_helper+0x5/0xb
Jan  3 15:21:35 DatenGrab kernel: Code: 89 df 81 c7 d4 04 00 00 75 21 68
90 0c 00 00 68 fb cd 2d e0 68 ef cf 2d e0 68 b0 d5 2d e0 68 61 d0 2d e0
e8 19 e1 e3 df 83 c4 14 <8a> 47 14 83 e8 05 3c 02 77 1b 83 e6 08 75 0c
c7 83 e4 05 00 00