[LG Optimus 2x] echo_21:
GPS performance not at maximum; lto.dat file not recognized

The topic of this post has been relaunched in its own thread here.

Sub-post 5 on Feb. 21st 2015

There is important news from my recent tests. I would say it is more bad than good news. But please read:

Setup: I flashed CM10.2 TheROM Build 22 new BL and copied a valid lto.dat to /data/gps . At the end of 2013 this setup provided GPS at maximum performance (definition unhide sub-post 1 below)

Observation: GPS does not work on maximum performance anymore. The glgps log file clearly shows that lto.file is not read properly:

...
01:28:25.676 &063256I @^@cc18BBAgAgKAOQLwMA2bz4/1AAAAA=
01:28:25.676 $063256I NVRAM reading complete.
01:28:25.676 $063256I Start reading LTO ...
01:28:25.676 $063256D LTO under license to 'lge', license #16
01:28:25.676 $063256D LTO_LICENSEE=lge
01:28:25.676 LTO file [/data/gps/lto.dat] opened for reading (fd=11)
01:28:25.687 $063267I LTO error code 17.1611
01:28:25.687 $063267I GPS LTO age 4.2d (361705s)
01:28:25.695 $063275I LTO error code 8.979
01:28:25.699 Closed LTO file (fd=11)
01:28:25.699 $063279I LTO reading complete 0.52332
01:28:25.699 &063279I @^@lt48CBBgwAAAAAAAAAAAAAAAAMAAAAAAAAAAAAAAAADAAAAAAAAAAAAAAAAAwAAAAAAAAAAAAAAAAQ
01:28:25.699 &063279I @^@lt44CCAGAhnQWoBKkhSPJN4f33VrbQDg1CAAAAAAAAAAAAAAAAIB8WQgAAAAAAAAAAAAAAAA==
01:28:25.699 $063279N LTO_BAD { }
01:28:25.699 $063279I Start reading CBEE file at LMS:35 GPS:1832 520121653(ms)
...

Conclusion: The fact that GPS does not run performantly on P990 with tonyp 's CM11 ROMs most probably does not depend in any issues that have been recenctly introduced.

Brainstorming: What may be the reasons why CM10.2 TheROM Build 22 (and as a consquence recent CM11 ROMs) don't show GPS maximum performance? Not sorted by probability or priority. Just as complete as possible.

/system/bin/glgps binary is not buggy but lto2.dat files downloaded from glgpals.com had sometimes after end of 2013 been changed in format that is incompatible with our glgps binary

there has always been an (e.g. date dependent) bug in /system/bin/glgps binary. In 2013 this bug had no consequences but became destructive somewhen after end of 2013.

/system/bin/glgps binary is not buggy and lto2.dat file format has not been changed since Nov. 2013. But lto2.dat could be encrypted and our P990's certificate for decription has been expired

the way i prepared P990 with CM10.2 in 2013 is different to the way I do in 2015 (AIO Toolkit 6.0; ROM flash TWRP 2.6.0.0). Could it be that AIO 6.0 or TWRP 2.6.0.0 make reading lto.dat mal-functioning?

Did I forget something?

Action Items (everbody please help!):

Try to find at least one tegra2 device that sucessfully makes use of glgps binary and lto.dat files. If found compare to our P990

Trial and error: replace our /system/bin/glgps binary by any other found in the internet

Prepare P990 with CM10.2 TheROM Build 22 the same way as in Nov. 2013. Test GPS performance again

Did I forget something?

Sub-post 4 on Feb. 20st 2015; GPS performance survey (originally posted here)

As you may know our P990 was able to work on GPS with maximum possible performance. Maximum performance means:

GPS Fix inside buildings (not too far away from windows; not in the cellar) in less than 20 seconds

GPS Fix with 8-9 sattelites inside buildings and 10-11 satelites outdoor

Without wifi and without SIM card (or with SIM but in air plane mode) GPS cold start fix after battery removal in less than 60 seconds

As you may also know many CM10.2 and CM11 ROMs do not show this maximum performance anymore. I would like to bring back this performance to all ROMs again.

All I first need is to know wich CM11 or CM10.2 ROM versions still work perfectly fine in the sense of GPS performance written above.

So please answer here if this is the case on your ROM. Do not forget to tell ROM name, date and kernel .

Please also reply here if you are unhappy with GPS..

Best regards echo_21

Sub-post 3 on Feb. 19th 2015 (originally posted here)

Thank you for remembrance! This is potentially good news. The "only" thing we have to do is to find and flash those GPS LTO working CM10.2 build to see if you are really right and GPS really works with "maximum performance". Then we have only to identify the difference between last GPS performant CM10.2 and first GPS non-performant CM10.2 build.

Do you remember a GPS performant CM10.2 build?

Sub-post 2 on Feb. 19th 2015 (originally posted here)

Luckily my wife has a P990 too. It runs on CM10.2 Dec. 2013 and I use it often as reference counterpart system to mine. Unfortunately it seems to have the same lto.dat problem by whatever reasons.

Yes I did. No success.

Sub-post 1 on Feb. 19th 2015

I am shocked! GPS is not working on its maximum performance anymore! Maximum performance means:

GPS Fix inside buildings (not too far away from windows; not in the cellar) in less than 20 seconds

GPS Fix with 8-9 sattelites inside buildings and 10-11 satelites outdoor

Without wifi and without SIM card (or with SIM but in air plane mode) GPS cold start fix after battery removal in less than 60 seconds

At least in 2013 our P990 really showed this performance with [MENTION=3605868]tonyp[/MENTION] 's CM10.2 . If you never observed this performance and don't believe me read these posts:

Witness [MENTION=5458952]breeno.net[/MENTION]:

http://xdaforums.com/showthread.php?p=47438823#post47438823

http://xdaforums.com/showthread.php?p=47448331#post47448331

http://xdaforums.com/showthread.php?p=47462987#post47462987

Witness [MENTION=4920940]sgspluss[/MENTION] http://xdaforums.com/showthread.php?p=47379987#post47379987

Witness [MENTION=4211084]tomsi91[/MENTION] http://xdaforums.com/showthread.php?p=47411198#post47411198

Witness [MENTION=5308871]FidiS[/MENTION] http://xdaforums.com/showthread.php?p=47415521#post47415521

Witness [MENTION=3046290]louiscypherbr[/MENTION] http://xdaforums.com/showthread.php?p=47403730#post47403730

Reference [MENTION=3605868]tonyp[/MENTION] (see aknowledgement in http://xdaforums.com/showthread.php?p=47706978#post47706978 )

Witness echo_21: believe me, or not :)

(Edit 02) Witness [MENTION=5160773]dev>null[/MENTION] http://xdaforums.com/showthread.php?p=58950812#post58950812

So my main target is to get exactly this performance back and nothing else. (Edit 01) It bases on the long term orbit (lto) data technology.

I am not interested in any other assisted GPS features that require internet connection via Wifi or mobile data nor that require data from the telefony cells! I am further not interested in any other GPS tweaks that e.g. only should correct the P990 clock (like top ntp).

I was able to get some log file from \system\bin\glgps when it processes the \data\gps\gldata.sto and \data\gps\lto.dat files. This clearly shows that someting is wrong with lto.dat:

...
09:04:41.663 &080583I @^@cc18BBAgAfKAOAtgUAOpUKAPj///8=
09:04:41.663 &080583I @^@cc18BBAgAgKAOAtgUAhMn4/1AAAAA=
09:04:41.663 $080583I NVRAM reading complete.
09:04:41.663 $080583I Start reading LTO ...
09:04:41.663 $080583D LTO under license to 'lge', license #16
09:04:41.663 $080583D LTO_LICENSEE=lge
09:04:41.663 LTO file [/data/gps/lto.dat] opened for reading (fd=12)
09:04:41.750 $080670I LTO error code 17.1611
09:04:41.750 $080670I GPS LTO age 0.2d (14681s)
09:04:41.758 $080678I LTO error code 8.979
09:04:41.772 $080692I GLNS LTO age 0.4d (36281s)
09:04:41.772 $080692I LTO error code 9.1017
09:04:41.773 Closed LTO file (fd=12)
09:04:41.773 $080693I LTO reading complete 0.88304
09:04:41.773 &080693I @^@lt48CBBgwAAAAAAAAAAAAAAAAMAAAAAAAAAAAAAAAADAAAAAAAAAAAAAAAAAwAAAAAAAAAAAAAAAAQ
09:04:41.773 &080693I @^@lt44CCAAmSl35PXr4mAEEDLmESgYBQIhBCAAAAAPDND0IAAAAAoDIZQgAAAABA3hhCAAAAAA==
09:04:41.773 $080693N LTO_BAD { }
09:04:41.773 $080693I Start reading CBEE file at LMS:760 GPS:1832 374697392(ms)
09:04:41.773 CBEE file [./gps/cbee.cbee] open failed No such file or directory!
09:04:41.773 $080693I CBEE file reading complete.
09:04:41.773 #080693D ->smRqRtr::wait4me(ME2PE_ME_IS_ON,0)
...

It seems that the /data/gps/lto.dat file is not recognized anymore even though [MENTION=3605868]tonyp[/MENTION] 's CM11 periodically downloads it correctly.

I will follow up in a subsequent post.