Re: Weird hard disk noise on shutdown (bug #7674)

[Robert Hancock <hancockr@shaw.ca>]

Rolf Offermanns wrote:
> I hear the same strange noise on poweroff (2.6.20 vanilla). This is what I
> get on my system with ATA_DEBUG and ATA_VERBOSE_DEBUG both defined. The
> system will *not* poweroff with "halt -f" so there was no noise!
> 
> md: stopping all md devices.
> Synchronizing SCSI cache for disk sda:
> ata_scsi_dump_cdb: CDB (1:0,0,0) 35 00 00 00 00 00 00 00 00
> ata_scsi_translate: ENTER
> ata1: ata_dev_select: ENTER, ata1: device 0, wait 1
> ata_tf_load_pio: device 0xA0
> ata_exec_command_pio: ata1: cmd 0xE7
> ata_scsi_translate: EXIT
> ata_host_intr: ata1: protocol 1 task_state 2
> ata_hsm_move: ata1: protocol 1 task_state 2 (dev_stat 0x50)
> ata_hsm_move: ata1: dev 0 command complete, drv_stat 0x50
> System halted.
> 
> If I do a sysrq-o right after this, the above message repeate once more and
> the system turns off w/o the disturbing noise.
> 
> For the next messages, I booted the system completely (no init=/bin/sh) and
> did a "poweroff" at the console prompt after the boot was completed. This
> time the noise was there.

 From these traces you can clearly see that no STANDBY IMMEDIATE 
(command code 0xE0) was issued before the power-off, which is what would 
prevent this problem.

If you wait long enough after halting before you power down, you may not 
get the noise, since many laptop drives unload the heads after a fairly 
short period of inactivity, and so the heads are already unloaded when 
the power is shut off.

-- 
Robert Hancock      Saskatoon, SK, Canada
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