[Q] Signal Lost with Screen Sleep

[j18ter]

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

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

 

[rootusr]

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

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?

 

[j18ter]

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?

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.

 

[rootusr]

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.

Thanks, I will try that..

 

[vro25]

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.

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.

 

[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

 

[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.

 

[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

 

[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%.

 

[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.

 

[fcasoli]

after rooting my Nexus, I locked again the bootload and installed 4.0.4, it works without problems...

 

[vro25]

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

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.

 

[balander]

No problem at all here... jakju 4.0.4

 

[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..

 

[puga74]

For me I just flashed back to my old 4.0.2 radio and the problem was gone. No issues as of now.

 

[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..

 

[qballe]

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..

for sure a wipe should solve seems to be a "corrupted istallation" IMHO

 

[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.

 

[kmso]

i do a clean install of 4.0.4 stock rom still have this problem

 

[vro25]

i do a clean install of 4.0.4 stock rom still have this problem

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.

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

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!