Rebooting quick-fix
 

The most common rebooting issue is the "32wd_to" (HW watchdog). A quick fix for this is described (buried) at https://bugs.maemo.org/show_bug.cgi?id=6334

Please, read through all the comments in that thread, and in particular read everything from Eero Tamminen (Nokia) at least three times :)

First you need to check if your rebooting problems are 32wd_to. This is done by opening the x-terminal just after a random reboot and typing:
"cat /proc/bootreason"
If the result is "32wd_to", then this quick fix will work.

The quick fix consists of disabling the device going to "deep sleep", and is done by:
The down side is that the battery will drain quicker when the phone is unused. I have tried it some days now, and with normal (phone)use it will last a day at least. No change when used continuosly.

My experience with this fix is a rock stable device, which is nice to have untill the bug is fixed permanently by Nokia :)

The device will not reboot while connected to a USB cable to a PC (it will reboot while connected to a charger). While doing the quick-fix, it is an idea to keep it connected.

Also, frequent reboots will sooner or later corrupt the file system, possibly "bricking" the device. After ANY random reboot it is therefore a good idea to use the on/off button for a cold reboot. It is also a good idea to reflash the device before this fix, to be sure the file system is OK, both firmware and eMMC.

From the Nokia board http://discussions.europe.nokia.com/...cending&page=1
After 17 random reboots in a row, the N900 is bricked. The link shows how to unbrick it. The importance of doing a manual cold restart (off/on) with power button is clearly strengthened.

Re: Rebooting quick-fix
 

I still find it questionable if this in fact CAN be fixed in software, other than your workaround which is not practical in the long term due to the extra battery usage.

If it happens to some peoples devices from fresh flashing and others never suffer it at all, it sounds more like a hardware problem. All I can think is Nokia are hoping its a minor glitch in the CPU that can somehow be bypassed using some sort of microcode update, though do ARM CPUs even have a microcode?

Re: Rebooting quick-fix
 

I don't pretend knowing what is going on internally with this watchdog, but as I understand it is essentially just a timer that is triggered (or not). I don't see any reason why this cannot be fixed with better drivers, since the reason could very well be that the driver does not "pet" it often enough when in normal operation, or the signal is a tad too short or some similar thing. The watchdog say "go to sleep" while the software is still in the middle of an operation. Again, not pretending I know something I don't, I would assume this is normal driver tuning.

Seemingly identical hardware often behave different, particularly regarding timers and interaction with software, this I do know by experience.

I don't think Nokia would say they believe they can fix this, if they actually believe opposite. But there is no guaranty that it actually will be fixed, intill it is, so I keep my fingers crossed :D

Re: Rebooting quick-fix
 

ok erm i am a total newbie on this,, what do i have to type into the x terminal to make this a tempoary fix as my machine is rebooting and stuff

is it just this

echo 0 > /sys/power/enable_off_mode

and what do i do to switch it back?


ok again i am a serious noob- permission denied(proc bootreason) what do i need to do to use to be able to access this sort of stuff..

Re: Rebooting quick-fix
 

I'm trying to do this, but I keep getting "Permission denied". What do I need to do to gain permission?

Re: Rebooting quick-fix
 

First you have to install a small app to get root access:
http://wiki.maemo.org/Root_access

Then open the terminal (x-term) and write:
root
then
echo 0 > /sys/power/enable_off_mode

To get it back to original condition, just reboot or write:
echo 1 > /sys/power/enable_off_mode

By far the best option is to make it permanent in the config file, as described.

Re: Rebooting quick-fix
 

thank you dude..


ok i take it rootsh is the best way- and type root b4 any command..


btw why is the permanent way better..

what is the difference(not specifics)- in practical terms.

Re: Rebooting quick-fix
 

Then you only have to do it once, and the change is permanent (untill you change it back), othervise you have to do it every time you reboot (turn on-off) etc. I don't think here are any other difference.

Re: Rebooting quick-fix
 

ok i installed rootsh

it is still saying permission denied

after

root

/proc/bootreason

Re: Rebooting quick-fix
 

Sorry, It is:
cat /proc/bootreason

I will update this. (you don't need root access for this though)

Re: Rebooting quick-fix
 

This did not work for me. Bootreason is 32wd_to. I restarted the device, and typed in what you wrote. About 3 hours later, I got a reboot. Any other ideas?

Re: Rebooting quick-fix
 

My understanding from the bug thread (link in the first post), is that this work around disables the watchdog. With this work around in place, you will not get this reebot-issue anymore, simply because the whole chabang is disabled.

If you still get reboots, this is due to some other fault, or you havent done it right (it is easy to type something wrong), or you havent done a proper hard reboot (power on off) so your device is still unstable, or a combination.

Check /proc/bootreason after each reboot.

Re: Rebooting quick-fix
 

Well maybe I am doing it wrong. Should it display something after I run the command? It just goes to the next line. But I'm pretty sure I typed everything in correctly.

Re: Rebooting quick-fix
 

No it should not display anything. But you can do the permanent fix, then you can view the file and be 100% sure.

Maybe you have another bug somewhere, did the last reboot show 32wd_to ?

But I am no expert on this. I did as Nokia suggested (the same thing as in the first post), and it works perfectly for me and apperantly for lots of others. I also tried reflashing, but that did not work. So what I did was:

Reflash again both eMMC and FW to be sure no files are corrupted by rebooting.
Apply the "permanent" fix.
Manual reboot (on off)
Since then everything has been working with no problems what so ever.

This is almost a week ago.

Re: Rebooting quick-fix
 

Hi


Can some help me for permanent fix

what are the commands for that.

thanx in advance

Re: Rebooting quick-fix
 

There is a step by step instruction at the bottom here:
http://discussions.europe.nokia.com/...cending&page=2

Re: Rebooting quick-fix
 

hey bsving or anyone else- the fix is very good(drains battery but ordered a spare ), how do i do the permanent fix--- i cant be bothered to get a replacement, and hopefully a firmware fix will come eventually.


i take it the fix can allways be reset back- but will stay on even if the n900 is switched of or rebooted.



EDIT lol i should perhaps read the updated thread b4 posting :)

Re: Rebooting quick-fix
 

gravis if you dont wanna flash first check this..one thing i noticed on the temp fix is that it doesnt allways work unless you cold reboot first, then straight away apply it(bsving has mentioned this)

also did you power of your phone- or did it run ouur of battery, and you didnt do the code once the unit is back on.

Re: Rebooting quick-fix
 

bsving mate please help me- i still cannot work our how to do the perm fix mate.. i would be veru appreciative of you couldtell me- the nokia forum isnt helping me much

do i need to edit the pmconig in vim?

and how?

thanks

Re: Rebooting quick-fix
 

all done - its good thanks again bsving

Re: Rebooting quick-fix
 

Just wanted to say that I did the permanent fix and I have't rebooted in almost six days (which is before I did the fix) so it's been rock solid. I definitely recommend doing the permanent fix. Thanks bsving!

Re: Rebooting quick-fix
 

Funny thing is I thought the reboot issues were "self imposed" until I got my second N900 and it started random reboots without any app installs. The second one rebooted over a dozen times for the time that I used it and that was mainly just to compare two N900's for 2G signal in "low bar" areas.

Re: Rebooting quick-fix
 

Well, at last this particular issue is as good as confirmet to be fixed:
https://bugs.maemo.org/show_bug.cgi?id=6334
:D

The really "funny" thing is that the Droid is having similar problems, just google "droid random reboot" or look here:
https://supportforums.motorola.com/t...6AC4AC97.node0

One theory is (by Nokia) that the Omap3 processor is not well adapted to the newest Linux kernals, or the other way around :D So, for all practical purposes this IS indeed a software bug. I mean, it looks like the problem is essentially that the newest Linux kernels are not robust enough to handle the natural spread in specs of the Omap3 processor regarding power management.

Re: Rebooting quick-fix
 

There are three or four types of reboot problems.

The Nokia tech guy on that bug said this:
"This bug contains many different reboot issues.

One set of issues is system service crashes. These seems to be quite rare in
this bug though.

Another set is crashes when the device is heavily used. This could be memory
management related issue (e.g. between CPU, GPU and DSP, they all can change
the memory mappings).

One set seems to be related to power management (device wakeup from sleep) and
happening more often on some specific devices, but it may be more of a slight
difference in how they behave than "hardware bug"[1].

Last set seems to be related to networking and an Oops in network related
functionality. This may be something that triggers based on what kind of a
network environment one has or traffic that network has.

Most of them so far seem to be triggering randomly, but that doesn't mean that
it would be a HW issue. Things that depend on power management, memory
management, network environment, timings etc on the kernel side, may get
triggered seemingly randomly when the device has as complex HW and SW
interactions as what e.g. N900 has.


The important thing is to check what kind of reboot is in the question; sw_rst
or 32wd_to, whether former was because of a critical system service
termination, or whether they were because of some specific kernel oops, or
whether 32wd_to was just due to device freezing (without Oops being logged) and
provide the information in which kind of situations these happen and steps
leading to it.

Based on that information from all of you, we can then try to come up with
specific steps where some *specific* reboot cause can be nearly always be
triggered within reasonable time (say 15 mins). After that finding the cause
for the bug and fixing it becomes much easier."

Also I want to say to all you guys.
Pull your battery out and check the contact pins on the battery.

On my N95 8gb I bought a cheap oversized Chinese mass manufactured battery from ebay and I get a reboot whenever I tap it too hard or jar it too hard because the contact pins on the battery spread apart as time goes on and a jolt will disconnect those two from pressing snuggly on each power terminal inside the phone.
Take a safety pin or thumb tack and press those two slightly together in all 3 slots so they will be more snug if you are getting reboot when you jar the phone or tap it on the back side.
I noticed the contact pins on my N900 battery move too much too easily from side to side when I adjusted them with the thumb tac for my peace of mind but they still seem to look like they will snug against the power terminals inside the phone.

Also I want to say that when you get your N900 and hook it up to your computer in mass storage mode don't create any folders or files on it that look similar to the ones that are there already on the N900.

If you're gonna stick stuff on it in mass storage mode make sure you put it in a directory that is very easy to remember (probably called your name or something like that) and has nothing to do with any of maemos folders or directories until we get the reboots figured out.

Don't create directories or folders like tmp usr bin images...
just type file: into the browser and you see all those folders there?
.dev, bin, boot, etc, dev all that stuff.... don't make any directories that have those names.
Why confuse the device?

I just created a constant annoying reboot issue by trying to install mojopac which put about 6 directories on the N900 that had folders that look very similar to folders already on the N900 and I'm sure it had a bunch of files with the same names or similar to maemo folders and names then I started installing apps after that and that's when i got constant reboot issues related to multi tasking.

I had to uninstall every app after that, that i had installed and erase every folder that i put on the N900 in mass storage mode from trying to stick mojopac on it and then i had to take the battery out and check contact pins and then put it back in and finally now my multi tasking or high cpu usage causes reboot is gone.
I can multi-task again. MY device is back.

Re: Rebooting quick-fix
 

The bug (6334) concerns problems with a watchdog timer. It will reboot straight out of the box with no additional apps installed. Bootreason is allways 32wd_to and to disable "deep sleep" will make it rock stable, as will connecting it to a PC with a USB cable, while using a charger will not.

What you are experiencing is completely different, and not related to the watchdog timer.

Re: Rebooting quick-fix
 

I was reading the bug report yesterday, and I may have interpreted it incorrectly, but I understood it as "deep sleep" won't be disabled, it will just be handled properly. At least I hope it's so. I would imagine that disabling the chipset's "deep sleep" feature would reduce its power saving (and thus battery lifetime) capabilities.

Re: Rebooting quick-fix
 

Disabling deep sleep will indeed reduce battery life, but the device can be used normally. So this fix is only a temporary work around. The real fix will not reduce battery life, but make the device work as expected (deep sleep enabled). But this fix is currently only tested at Nokia labs, and not available yet.

Re: Rebooting quick-fix
 

Hi bsving,
I was reading through all your posts and I think you could possibly provide a solution to my reboot problem in N900. My N900 reboots right out of the box. The problem is, once I switch it on - it constantly keeps swtching off and on every 5 secs which makes it impossible for me to even navigate through the menu screens.

I read your post which said "The bug (6334) concerns problems with a watchdog timer. It will reboot straight out of the box with no additional apps installed. Bootreason is allways 32wd_to and to disable "deep sleep" will make it rock stable, as will connecting it to a PC with a USB cable, while using a charger will not."

However I'm not sure on how to disable "deep sleep". Any suggestion or solution would be of great help to me. Thanks!

Re: Rebooting quick-fix
 

1. check your battery contacts.

2. read this thread from the beginning

3. ????

4. profit

Re: Rebooting quick-fix
 

Go to the first post in this thread, the info is there. Keep it connected with the USB charger. If it still reboots while connected with a USB, then you don't have the problem that this fix gives a work around for.

Re: Rebooting quick-fix
 

Thanks ossipena and bsving. I tried those options too, but to no avail. It still kept rebooting when connected via USB cable to the PC. PC detects the fone and tries to install the driver and then the fone switches off and PC notifies saying "The driver installation failed". The same process repeats when the phone keeps rebooting. However I'm able to access the folders in the disk space/folders (32GB) of N900.

Do you think updating the firmware and flashing the device might make the phone work?

Re: Rebooting quick-fix
 

The cpu will still go to sleep while the device is charging, so I don't see that as a valid test of anything.

What we're dealing with here is not a problem with the watchdog. That's just the feature that reboots the device for you once it freezes. From the comments Nokia devs have made on bug 6334, it is apparently some kind of linux kernel bug involving the CPU power management that is triggered much more frequently for certain N900s depending on some unknown component variation in the electronics.

Re: Rebooting quick-fix
 

could you type to xterm:

and write here what the output of cat-command is?

it most probably is sw_rst or 32wd_to

but let's see what it is and continue after that is clear.

Re: Rebooting quick-fix
 

Is there a way to do that from a PC without having to touch the N900? The reason I ask this is, I never even got a chance to explore what are the options under the menu screen in my N900. My phone continuously keeps restarting as soon as I start it, barely giving me 5-10 seconds to view the menu screen.

Re: Rebooting quick-fix
 

No, only when connected to the charger, not when connected to the PC with USB. Don't ask me why, but it is a fact :)

Julian, try turn it off (take out the batteries, if it reboots to quick and put them back in). Then connect it to the USB when it is off. Let the PC install (or not) drivers. Then when it is connected, turn it on.

However, conecting it with USB is one of the things that will stop rebooting for this particular problem, so you may have a different problem.

Re: Rebooting quick-fix
 

Ok. This is what I did now. Removed the battery from N900. Inserted battery back after sometime. N900 did not start by itself. Plugged the USB cable and connected it between N900 and PC. N900's glowing light started to blink indicating that its being charged. N900 still did not switch on by itself. Then I powered on my N900. I went till the menu screen (10 seconds) and then I got an error in an yellow line on the menu screen saying "Internal error. Application 'Camera' closed." And then the usual process of continuous reboot started to occur while connected to the PC itself.

Re: Rebooting quick-fix
 

Well, it looks like something else than this thread is about. You can try to reflash the device:
http://wiki.maemo.org/Updating_the_tablet_firmware
Maybe you should leave it on the charger, while leaving it off, for a while first, so your battery is charged.

Re: Rebooting quick-fix
 

So how common is this problem?

I got my N900 earlier and it had this issue, so I took it back in and got another one and even this one suffers from the same thing!

I think I'm going to try and get a third one since I expect that something this expensive should work properly...

Re: Rebooting quick-fix
 

Apperently about 20 percent of the production units are like this. The last I have heard is that it is an issue with the Omap3 processor and relatively new Linux kernels. The droid also suffer from this bug.

Re: Rebooting quick-fix
 

Hey guys, some good news finally!!! I tried to flash my device and Aloha! It worked. I've been using my N900 for 3 hours now. So far no reboots, working absolutely fine. So I guess the issue for me was with the Maemo OS. Anyone facing this continuous reboot issue, try to follow the instructions given in http://wiki.maemo.org/Updating_the_tablet_firmware to flash the device.
Thanks to everyone (especially bsving) who had the patience to answer each of my questions.