[ltp] G41 ticking

[Peter B. West]

Another ticking ThinkPad.  Ever since I first loaded gentoo on my G41 
(just after I got the machine) it has had an intermittent annoying 
ticking.  Generally it's a monotone at about 4-5 Hz, although sometimes 
there is a more rhythmical pattern.  The timing was unpredictable, but 
when it started, it would usually go on, with occasional pauses, for 
extended periods.  I tend to leave it running all the time, and would 
find it ticking away in the morning or the middle of the night.

After a while I realized it was the disk.  Anything that involved disk 
activity would silence the ticking briefly.  I looked around for some 
process that might be writing to the disk in the background.  No luck.

When I fired up laptop-mode with a short disk timeout while on AC power, 
the problem went away as soon as the drive spun down, nicely 
demonstrating that 1) it was the disk, and 2) it was not being written 
to by some background process.

Not wanting to be spinning the disk up and down in normal usage, I 
experimented with some of the hdparm settings which were also in 
/etc/laptop-mode/laptop-mode.conf.

I can't be entirely sure yet, but it seems that changing the power 
management setting (-B) to 254 has solved the problem.  I haven't heard 
the ticking since I set that value for AC running.

Peter
-- 
Peter B. West <http://cv.pbw.id.au/>
Folio <http://defoe.sourceforge.net/folio/>
<http://folio.bkbits.net/> <- the atTridged version
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