[maemo-developers] [maemo-developers] RE: defective memory?

[From: Siarhei Siamashka]

On 9/19/06, Kimmo Hämäläinen <kimmo.hamalainen at nokia.com> wrote:

> Yes, it would need to be reproducible in several different devices. The
> guy here that tried to reproduce it currently thinks that Siarhei's unit
> is broken.

Yes, I also think that the probability of my device being broken is
quite high. A certain (small) fraction of other Nokia 770 owners are
probably having the same problem. Does it make the device completely
useless? Of course no, my device works almost fine, it only crashes
and reboots sometimes, I also has filesystem corruption several times
(now even switched mmc filesystem to ext3, don't know if it would help
much though). So the device can be surely used as a book reader,
internet browser and serve other tasks. Other (small) fraction of
users who got 'white screen of death' were surely less lucky.

What can be done about this if the defective memory problem gets
confirmed. I see three possible ways:
1. 'Ignorance is a bliss' - just do nothing, those who don't know
about the problem will not worry about it :) The device will just
crash or reboot occasionally, some more unlucky users having more
annoying crashes will complain in the forums providing some bad PR.
2. Distribute some diagnostics software that will help to identify
memory problems and repair/replace defective units, that will have
some expences, but will improve overall reliability and reduce the
number of negative publicity.
3. Add some (un)official support for working around bad memory regions
using technology something similar to BadRAM, in this case most of
such units will be completely usable.

In general, bad memory problem is quite common for x86 pc's, but there
is an excellent tool for memory diagnostics - memtest86. It helped me
quite a number of times, also I always advice everyone having
stability issues to run it first. I don't know how the reliability of
memory chips used in embedded devices compares to the reliability of
memory from normal desktop computers, but bad memory seems to be one
of the most frequently encountered hardware problems.