According to Manuel Bouyer:
>
>Do you have any power management enabled for this drive ? 

``sometimes'' I have set up the apm scripts to do power management on
the drive when the laptop is running on battery.  When it is running
on line power the power management is off.  The bios power management
is disabled.

>This behavior looks familiar, this week-end I tried a drive which
>doesn't work with my Promise atapter, it spins down when the Promise's firmware
>probes it. It works more-or-less properly when connected to a PIIX3 ...
>

Mine seems to work fine most of the time but some things will make it
lock up.  The most likely thing to make it lock up is a make depend
during a kernel build, I have had it lock up at random during a
restore and during fsck - always during fairly heavy disk access.  I
did try turning on the wdc_debug stuff and had a look at what that
said, the last block before the machine locked up went like this:


wdstrategy(wd0)
wdstart wd0
wdc_ata_bio_start wdc0:0:0
_wdc_ata_bio_start wdc0:0:0
wdc_ata_bio_intr wdc0:0:0
wdc_ata_bio_done wdc0:0:0 flags 0x0
wdc_ata_ata_done: wddone
wddone wd0
wdstart wd0
wdcstart from wdc_ata_done, flags 0x0
<hangs here>

This is typed from a handwritten scrawl so something may have been
lost in the translation.  The above call pattern is always the same
when the machine hangs, but it looks like a normal sequence to me so I
don't think that this proves much...

The machine operates correctly for my "normal" usage pattern of
editing & compiling small bits of code even with the power management
running and the disk spinning down after a few seconds inactivity.  I
just don't seem to be able to build a kernel.

I am trying to see if I can get/borrow a similar drive to try and
eliminate a hardware/firmware fault.

-- 
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Brett Lymn, Computer Systems Administrator, BAE SYSTEMS
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