yashsingh1/xdaforums huggingface dataset:
[Samsung Galaxy Nexus] nicholasbgr:
This was the first thing i tried since I'm from Brazil and UIKKL3 is the brazilian radio and it didn't fix it for me.

What I find curious is that the issue is a little different on my phone, the signal doesn't dies for good, it just becomes intermittent.

Setting the minimum clock to 700mhz did seem to "fix" it for me but I'm afraid the battery hit wont be gentle.

Here's what I found about the feature he advises to turn off (Smart Reflex)

Smart Reflex

The variations in the silicon manufacturing processes are responsible for the difference in performance and/or power consumption of the device. Adaptive Voltage Scaling- AVS, implemented with SmartReflex(TM) technology, tends to narrow this difference.

Dedicated SmartReflex hardware implements a feedback loop - without processor intervention - which optimizes the voltage levels to account for differences in the manufacturing process, temperature and silicon degradation.

To enable smart reflex

# echo 1 > /debug/voltage/vdd_core/smartreflex/autocomp

# echo 1 > /debug/voltage/vdd_mpu/smartreflex/autocomp

To disable smart reflex

# echo 0 > /debug/voltage/vdd_core/smartreflex/autocomp

# echo 0 > /debug/voltage/vdd_mpu/smartreflex/autocomp

Impact on Power Consuption on Android System

This feature is hardware controlled after initialization. Initialization is done from the kernel. Android Power management is completely unaware of smart reflex.

Power consumption is reduced since the operating voltage is lowered for each operating point in which the device is operating in.

To minimize the power consumption in runtime

The maximum power reduction in runtime is achieved when “enable_off_mode”, “sleep_while_idle”and “smart reflex” options are enabled and dvfs option is set to “power save”.

To minimize the power consumption in suspend

The maximum power reduction in suspend is achieved when “enable_off_mode”, “sleep_while_idle”and “smart reflex” options are enabled and UART console timeouts are set.

Please check the power consumption analysis at http://processors.wiki.ti.com/index.php/Android_Benchmarks_DevKit2.3.4v2.1#Power_Management

http://processors.wiki.ti.com/index...d-2.3.4-DevKit-2.1_PortingGuides#Smart_Reflex
[Samsung Galaxy Nexus] rob61280:
I tried XXLA2 and UGLC1 and the signal drop persisted with both. I then went back to UGLA4 and I have not experienced a dropped signal in 24 hours.

Your mileage may vary depending of your location and operator, I live in the U.K. but the North American radio suits my phone better, its worth trying a few of radios before assuming you have a hardware fault.

Also in the past fugumod kernels have helped when I had this issue on 4.0.3

R
[Samsung Galaxy Nexus] j18ter:
Had the opposite experience here, after installing the yakju OTA upgrade, which left me with the XXLA2 radio, it seemed the signal was dropping quite low, but it never went away completely, not even when the device goes to sleep. Still, it seemed lower than under 4.0.2, so I tried UGLC1, which is supposedly optimized for North America. This doesn't work for me at all, regularly losing the signal completely when it goes to sleep. So I went back to XXLA2 from Google's 4.0.4 factory build for now.

[update] It turns out both radios drop signal when the device goes to sleep, not always, but enough to make this 4.0.4 upgrade a show-stopper. So what is the best work-around? Rooting and controlling the CPU frequency?
[Samsung Galaxy Nexus] memoreks:
Update from Google

This was posted to the issue on Google's website:

Comment #19 on issue 28133 by mobile-g...@google.com: Signal lost when Galaxy Nexus is in Standby/idle - Android 4.0.4 Only

---------------------------------------------------------------------------

Hi folks,

In order to look into this issue on our side, we'd like to collect bugreport.txt files from those who received the OTA update to and remain on Android 4.0.4.

If you're experiencing a loss of signal during sleep after the 4.0.4 update, follow the instructions below:

support[dot]google[dot]com/mobile/bin/request.py?&src=6279961&contact_type=android_bugreport

(Note that this link is only valid for reports about signal loss)

We appreciate this information as we look into your reports,

Ethan

-------------------------------------------------------------------------

I've unfortunately rooted mine to fix it, as it is my work phone and thus I can't mess too much with it, but anyone who can recreate this issue please update the bur report via the link above, and Google will be looking into it.
[Samsung Galaxy Nexus] blair287:
I have this issue too on CM9 700mhz thingy fixed mine so far but yea battery taking a hit.
[Samsung Galaxy Nexus] dosmage:
As previously mentioned in this post, in the open issue with Android someone has asked us to generate bug reports and submit them. I've reflashed my phone and submitted one as well as what appears to be 3 others before me. If you are experiencing this problem I highly encourage you to do so they can get an idea of the impact.
[Samsung Galaxy Nexus] blair287:
Anyway to solve this without clocking cpu up to 700mhz and battery go down fast.
[Samsung Galaxy Nexus] andQlimax:
this is the correct link to report the signal lost issue only:

Android Bug Report

Stock 4.0.4 only
[Samsung Galaxy Nexus] Hidjes:
You have to prevent to let the phone go into deep sleep.

You can do this by setting (in SetCPU for example) not at a minimum of for example 200GHZ but a little bit higher, so it is awakened all the time. GL
[Samsung Galaxy Nexus] j18ter:
I tried the other recommended fix, namely to root the phone and then use adb to change the following kernel variable from 1 to 0, i.e.,

su

cd /sys/kernel/debug/smartreflex/sr_core

echo 0 > autocomp

Contrary to what an earlier post may have implied, this doesn't require using a custom kernel. I've done this with the stock kernel in 4.0.4, and since then the signal hasn't been dropped. I'm guessing this setting will be lost after reboot, so a more permanent way to set this is needed. I don't know the impact on battery consumption yet.

J
[Samsung Galaxy Nexus] memoreks:
Battery life

While I haven't got proper metrics to back it up (I have a day job!), I haven't found the battery life of 4.0.4 with the 700mhz fix applied, to be any different to 4.0.2 battery life.

As a rough guide, my GNexus with a 4.0.4 ROM and the "700mhz fix" applied has lost on average 2.4% per hour today, with 3-4 phone calls and a bit of light usage. This is kind of what I expect from a modern smartphone without going crazy on custom kernels etc.

If your GNexus is disconnecting from the GSM network for long periods of time with an unfixed 4.0.4 ROM, then its bound to improve battery life as it is not keeping in contact with a cellular base station, and is powering down the relevant radio parts of the phone.

If anyone has the spare time, then it would be interesting to compare battery utilisation between a working 4.0.2 and a fixed 4.0.4 installation, and see if the 700mhz increase makes much difference. My guess is that it won't.
[Samsung Galaxy Nexus] allio:
I think you're broadly right, that 4.0.4 with the 700MHz "fix" probably behaves similarly to 4.0.2.

In my experience, this isn't true. The constant attempts to re-establish the signal actually prevent the phone from going to sleep at all. I rebooted my phone half an hour ago and it has probably one minute of screen on-time since then, but it's been awake 95% of that time due to the constant disconnections and attempts to reestablish the network link. Battery life is plummeting like a stone as a result - 6-7% in half an hour.

I believe the 4.0.4 update has enabled some more aggressive power saving techniques (smartreflex) that weren't used in 4.0.2. This is resulting in greatly improved battery life for most people. Unfortunately, on certain devices (such as ours), it's proving to be problematic.

Clearly it needs a fix from Google - I just hope the fix results in us getting the same power savings everybody else does, and doesn't leave us out in the cold by simply turning off the feature.

I've submitted my log and starred the bug report.
[Samsung Galaxy Nexus] rootusr:
UPDATE: not :( It's not working, after a some idle time I'm losing connectivity again...seems that the only option is to modify CPU frencuencies

Having the same problem with Stock rooted YAKJU since the update to 4.0.4.

I can't understand why since seems to be a Kernel issue but i flashed UGLA4 and the problem went away... so, is this really a Kernel problem?

I already report this to google.
[Samsung Galaxy Nexus] j18ter:
Forcing higher CPU frequencies is not the only option. With the phone rooted, the following commands from a terminal emulator or via xda also seem to fix the issue, and still allow the phone to idle at low frequency:

su

cd /sys/kernel/debug/smartreflex/sr_core

echo 0 > autocomp
[Samsung Galaxy Nexus] rootusr:
Thanks for the tip, can you please explain what that change does? impacts battery or something else?

I'm also assuming that this change remains only until you reboot.. right?
[Samsung Galaxy Nexus] j18ter:
Apparently, this disables a new feature, which attempts to fine-tune the core voltage for further reduction of power consumption. This fix was discovered by one of the custom kernel guys, you can probably find more details by searching the developer forums.

Yes, this needs to be done after every reboot, unless it is put in a startup script. I'm hoping Google will fix the issue soon, so I'm not too worried about a permanent solution at this point.
[Samsung Galaxy Nexus] rootusr:
Thanks, I will try that..
[Samsung Galaxy Nexus] vro25:
I had the sleep disconnect issue on 4.0.4 on my Nexus. As per my battery history, Cell Standby was by far the biggest battery drain. It was regularly over 40% without a signal. The fact that there is no signal does not mean the phone is saving battery as the phone is SUPPOSED to have a cell signal - unless in Airplane Mode - so it stays awake trying to establish a signal.

Changing radios does not resolve the issue. It affect upgraded ROMs, full yakju 4.0.4 factory image and even AOKP ROMs.

The only way I've been able to resolve the issue is to use a 4.0.2 image.
[Samsung Galaxy Nexus] 1wayjonny:
I am not having issues did you guys also update your bootloader?

The update should have you on the new radio with the new bootloader, it is possible to have issues when they are not the correct combo.

You guys should post how you flashed , which packages, the bootloader and current radio you are using.

Hope this helps
[Samsung Galaxy Nexus] cmstlist:
I'm using yakju 4.0.4 on an i9250 on Wind Mobile (AWS band HSPA carrier) in Canada. I am *not* experiencing this bug, but for what it's worth I flashed back to UGLA4 radio rather than either of the radios that came with 4.0.4. Yesterday at the end of the day I checked my battery graph screen and did not see any disconnects except for ones that corresponded legitimately to locations where my phone was blocked from receiving a signal.
[Samsung Galaxy Nexus] robrob777:
No problem here either.

I didn't go the official way, Wisely I waited for a CWR zip file to update only the build, not the bootloader or Radio.

Runing AOKP 29, with Jame bond kernel at 350mhz min
[Samsung Galaxy Nexus] AkaZn:
I fixed the problem by flashing an old radio I9250XXKK6. Haven't had signal lost since then.

I'm on yakju, Tmobile. Upgrade to official IMM76D and lost signal 100%.
[Samsung Galaxy Nexus] elgorra:
Didn't flash the 404 radio and not having problems

Hi. I'm not experiencing problems but since I upgraded from yakjuxw I didn't flash the new radio.
[Samsung Galaxy Nexus] fcasoli:
after rooting my Nexus, I locked again the bootload and installed 4.0.4, it works without problems...
[Samsung Galaxy Nexus] vro25:
I flashed factory yakju 4.0.4 image and I tried upgrading from yakju 4.0.2 and yakjuux 4.0.2. I've also tried different radios once on 4.0.4. Nothing resolves the issue. The only fix is re-flashing 4.0.2.

As per Google's dev site, radios and bootloaders are generally backwards compatible - so old radio/bootloaders are compatible with an newer firmware but not the other way around.
[Samsung Galaxy Nexus] balander:
No problem at all here... jakju 4.0.4
[Samsung Galaxy Nexus] juxli125:
got this on stock rom 4.0.4 and cm9 too; after update of radio to newest it works so far with no problems..
[Samsung Galaxy Nexus] puga74:
For me I just flashed back to my old 4.0.2 radio and the problem was gone. No issues as of now.
[Samsung Galaxy Nexus] Nicao:
I got an OTA update 3 days ago

since then my signal, camera (only blackscreen), mail (loosing mails, deleting inbox) and display dim (not reacting) is crapped..

since this thread is only for the signal issues i can report that when using WLAN and HSDPA at the same time both keep on dropping (icons get grey, fully disappear so only battery icon is left, appear in grey again, connect again).. happends randomly and about every 5-10 minutes once or twice in a row.. :(
[Samsung Galaxy Nexus] qballe:
for sure a wipe should solve ;) seems to be a "corrupted istallation" IMHO :o
[Samsung Galaxy Nexus] memoreks:
So to clear this up

Initially I installed the OTA upgrade over the top of my existing 4.0.2 ROM. This is when I first experienced the issue.

In an attempt to solve it, I then wiped data/cache, and installed the 4.0.4 stock ROM downloaded directly from google. Still got the same issue.

So far, I have just moved the minimum CPU speed to 700mhz. The abd fix is fine as long as you never need to reboot your phone away from a PC, but for me this would be a PITA, so I sacrificed a bit of battery life for the ability to reboot my phone whilst AFK.

I'm very glad some of you aren't experiencing the issue, but nearly 500 people have starred it on the Android issues website, indicating this is not an isolated incident.

Google have asked several people for permission to send their debug files to Samsung to assist with the fix, so things seem to be moving in the right direction, however the issue is still not assigned to anyone, and is currently still a Medium severity.
[Samsung Galaxy Nexus] kmso:
i do a clean install of 4.0.4 stock rom still have this problem
[Samsung Galaxy Nexus] vro25:
I don't think you're having the same issue. I also don't think that people who resolved the problem with new (old) radios are experiencing the same issue. This is not a "I sometimes lose signal" issue.

The issue as described is very easy to replicate - turn off wifi and then turn off the screen. Wait 5 minutes and try to call your phone - it will not work if you have this issue. When you power the screen back on you may see that you have signal, this looks to be just a cached image, after a second of so you will notice an "x" in the signal bar.

This worked for me! Yes, it would be a pain in the ass to do whenever you reboot, but if you've already rooted your phone and shelled in to type that command it should not be a big deal to write a script to do it.

My Linux is not the greatest, but I think this should work too:

sudo echo 0 > /sys/kernel/debug/smartreflex/sr_core/autocomp

Does anyone know what script to add this to so it will execute on startup?

**Update**

I found a simple way to run the fix at boot!
[Samsung Galaxy Nexus] mobilehavoc:
I'm on 4.0.4 stock unrooted and locked boot loader on a yakju build GSM Nexus running on TMobile US. I have tried a lot but can't replicate this problem. My signal remains active in deep sleep and I get great battery life. Not sure why I'm immune to these changes. I got the ota and didn't flash anything. Here's hoping I'm one of the lucky ones.
[Samsung Galaxy Nexus] Hash_Map:
I am on yakju, AOKP 4.0.4 with the latest boot-loader, radio images from Google and Franco's kernel r121.

I followed the reproduction steps above but I can't replicate the radio issue. Even in bad reception areas I still get calls right after standby or deep sleep.
[Samsung Galaxy Nexus] vro25:
I'm sure you're fine. It can't be *that* common a problem or they would have caught it during QA of the firmware.

I would think the hardware is the same and the main difference is the carriers so the issue should effect everyone on a particular network provider. This doesn't seem to be the case as @efrant is on the same carrier as I am but he's not having the issue. It may be that I have no background apps pulling data so my phone goes to sleep quicker than others - my battery drain is normally about 1% per hour when the screen is off - so it goes to sleep pretty quick.
[Samsung Galaxy Nexus] cmstlist:
Perhaps this issue only produces signal drops on certain radio bands? Have any users with AWS band carriers (T-Mobile HSPA, WIND Mobile, Mobilicity, Videotron) been getting this?
[Samsung Galaxy Nexus] 9numbernine9:
WIND Mobile customer here - I haven't been able to reproduce this issue. Using AOKP Build 29 (based on 4.0.4), baseband UGLA4.
[Samsung Galaxy Nexus] tropmonky:
I'm in Los Angeles on T-Mobile here. Running full flash of yakju 4.0.4 downloaded from Google. My phone looses signal every time it goes to sleep. This issue only started when moving from 4.0.2 STOCK to 4.0.4 STOCK. I reverted back to the 4.0.2 STOCK and it's fine, tried going back to 4.0.4 stock (redownloaded the rom from google the day after it was posted) and had the same exact issue, even after multiple reboots of the phone. I tried it for a full day, missed all kinds of phone calls, emails, txt msgs, ect.

I've had to flash back to 4.0.2 in order to make it work properly. I'm wondering if I may sell this thing and pick up a new HTC phone when they hit the shores.... or heck, I may blow the dust off my Nexus One and just use that again.
[Samsung Galaxy Nexus] astropods:
Manual flash?

Did the posters with this problem do a manual flash or get the ota notification? I'm on tmobile usa and updated with the ota notification and don't have the issue. All stock..
[Samsung Galaxy Nexus] mobilehavoc:
+1 I did the ota not flash and no issues.
[Samsung Galaxy Nexus] sblantipodi:
Hi all,

have you understood what is the problem that creates the problem?

What phones are afflicted?
[Samsung Galaxy Nexus] apinto270:
gsm sim free UK galaxy nexus

No problems with mine, i think that the signal is even better after the update to 4.0.4, not rooted phone
[Samsung Galaxy Nexus] allio:
I've tried using SIM cards from two different carriers (using different frequencies) with absolutely no difference.

My guess is hardware variation.
[Samsung Galaxy Nexus] memoreks:
Things should start moving now...

Having checked on Google News, a lot of industry wags are now publishing news stories about the signal issue with the 4.0.4 update:

https://www.google.co.uk/search?hl=en&gl=uk&tbm=nws&q=galaxy+nexus+signal+&oq=galaxy+nexus+signal

Hopefully with the press reporting it, Google will move swiftly to issue a fix ASAP :D

Here's hoping...
[Samsung Galaxy Nexus] vro25:
Better Test & Easy Fix (req. root)

I've found a much better way to identify the signal drop issue and I've also found an app that will run a script at boot to disable the auto voltage setting. My phone has been rock solid in testing all day. The fix requires root access (just like the command line method) so it may not be for everyone - but if you've got an unlocked bootloader you might as well give this a try.

Easy Test For Issue

The quickest way to see if you have the issue is to do the following with the phone unplugged from charger or computer:

1. (Optional, but recommended) Install "No Signal Alert" from the Market.

2. Disable wifi.

3. Disable mobile data (Settings->Data Usage->Mobile Data OFF).

4. Set your display timeout to 30 seconds.

5. Reboot your phone.

7. Wait for you display to go to sleep (30 seconds after boot).

8. If you installed No Signal Alert you should hear a beep within the next 30 seconds, otherwise wait 30 seconds, power on your screen to check your signal. If you have the issue you will see your signal has dropped. With No Signal Alert installed, if I manually turn off the display my phone will beep within 5 seconds because I've lost signal.

It would be interesting to get feedback from people on 4.0.4 who aren't seeing the issue. Wonder if a few begin to see it by following the above steps.

Disabling data seems to accelerate the issue - presumably because the radio is not being used to send data so it goes to sleep much quicker...

Easy Fix For Issue

This will require you have superuser.apk installed.

1. Unzip the attached script (radiosaver.sh) to /sdcard on your phone.

2. Download and run "Script Manager" from the Market.

3. From within Script Manager, click on radiosaver.sh file in /sdcard.

4. Click the Su and Boot icons to grant superuser and run at boot (see attached).

5. Click Save, exit the app and reboot your phone.

6. Upon reboot the app will request superuser permissions, click yes.

If everything was done properly then run through the test above and you should still have signal. Don't forget to re-enable data & wife when you're done ;-)

The attached script just contains the following command to disable auto voltage as suggested earlier in this thread:

echo 0 > /sys/kernel/debug/smartreflex/sr_core/autocomp

Like I said, for me it didn't matter what radio I was on or what ROM, if I'm running 4.0.4 it would just fail. Also, I also tried a SIM from Wind (different provider) and it also failed.

Hope this helps at least preserve battery life for those who were using the SetCPU fix. Good luck!
[Samsung Galaxy Nexus] rootusr:
Thanks I have been doing this manually but this is much better.

For all of you who are not having the problem please try vro25 steps to reproduce it. I have found a lot of users that have not noticed yet. Also please check the open issue link in google and send your bugreport, star the thread and let us know if you find better solutions

Thank you all!
[Samsung Galaxy Nexus] tacz:
Hi guys,

It seems like mine Nexus is not affected by signal drop as I tried to replicate the problem as written above but couldn't(waited for approx. 10 minutes but no signal loss notification at all) also tried to call my phone several times (with 2, 5, 10, 15 minutes intervals) and no problem. I'm on yakju 4.0.4 IMM76D, baseband I9250XXLA2 flashed by fastboot method, on Vietnamese 3G network. Isn't it country specific problem?

Also to add to be more specific: my Nexus is from the "Made in Korea" batch
[Samsung Galaxy Nexus] vro25:
Could be carrier or hardware or both, still not enough information to determine which.

I'd like to hear from people on stock 4.0.4 (modified kernels might not exhibit this issue) on Canadian carriers like me who are not experiencing the issue so we can try to figure out what's different with their phones.
[Samsung Galaxy Nexus] rootusr:
Wait more time, some users have reported that it starts happening after a long period of inactivity, maybe some apps on background are keeping your cpu active avoiding IDle. Also please notice that the problem is not occurring when the device is connected to computer or the wall charger.

I'm not saying that you have the problem just let's be sure that really is not happening and find out whats is different than in your device which would be really useful for all.

Thank you
[Samsung Galaxy Nexus] msedek:
Same problem here, just noticed i dont lose wifi cuz im on wifi keep alive but when i got back to gsm the bars are gray with no symbol no E or H or 3G so i guess its the same you all are experiencing, just bought setcpu and testing
[Samsung Galaxy Nexus] ceejay83:
i've been getting E/H symbols with grayed out signal bars. i don't get any data, i have to toggle airplane mode to get it working again.

on aokp 29 with ugla4
[Samsung Galaxy Nexus] tacz:
Ok, I'll try to have it being idle for longer time at night as in the day its hard to have it idle longer than 15-20 minutes as always being interrupted by a call, e-mail or message. I'll try to turn of my e-mail sync as well.
[Samsung Galaxy Nexus] sblantipodi:
my phone stock 4.0.4 does not suffer of this problem.

have you understood what phones suffers this problem and why?