Xperia XZ with Nougat 7.0 random restarts caused by diag_mdlog

[MaxAb]

Hi,

recently i got a new Sony Xperia XZ device (F8331) and taken it in use after upgrading to the latest firmware available:

39.2.A.0.417 (customization variant: 1305-1010 R5C)

after a i few crashes, i did the SW Repair with PC Companion app for Mac and did NOT restored any backup but reinstalled apps one-by-one from the PlayStore.

Still, it restarts randomly ( a few times per day) or freezes into black during the night.  

i took bugreports after each restart and see from each tombstone file that /system/bin/diag_mdlog causes restart.

Build fingerprint: 'Sony/F8331/F8331:7.0/39.2.A.0.417/1528746196:user/release-keys'
Revision: '0'
ABI: 'arm64'
pid: 9260, tid: 9260, name: diag_mdlog >>> /system/bin/diag_mdlog <<<
signal 6 (SIGABRT), code -6 (SI_TKILL), fault addr --------

backtrace:
#00 pc 0000000000074424 /system/bin/linker64 (__dl_tgkill+8)
#01 pc 00000000000738a8 /system/bin/linker64 (__dl_pthread_kill+64)
#02 pc 0000000000067328 /system/bin/linker64 (__dl_raise+24)
#03 pc 0000000000064d48 /system/bin/linker64 (__dl_abort+52)
#04 pc 0000000000066df0 /system/bin/linker64 (__dl___libc_fatal+104)
#05 pc 000000000000fddc /system/bin/linker64 (__dl__ZL29__linker_init_post_relocationR19KernelArgumentBlocky+3636)
#06 pc 000000000000ef08 /system/bin/linker64 (__dl___linker_init+528)
#07 pc 0000000000006db8 /system/bin/linker64 (_start+4)

diag_mdlog is QC tool: https://osmocom.org/projects/quectel-modems/wiki/Diag_mdlog

i could not find it in my device /system/bin/ folder , was it linked by mistake from debug build configuration

into the production build ?

How this can be fixed ?  my device is not rooted so i cannot modify the system props.

[MarlonUk1]

i would suggest another go at software repair using Xperia companion but this time do not install any apps first, observe your device for a few hours/days, to see if restarts again

[MaxAb]

The crash happened in the system app , i doubt that it would help reflashing with the same firmware. 

But to insure that, i've restarted the device in the SAFEMODE, where all downloaded apps are disabled.

after about half an hour another restart happened.

but unfortunately it did not create the tombstone file in the safemode, so i cannot say what was the reason for latter restart.

Looks alike the tombstone is not created for every restart but Xperia Care app detects and logs the System incident accurately.

Also, i have enabled Advanced Logging there, hoping it will help to identify the problem.

[NeoBeum]

You could do dumpsys in USB Debugging

https://source.android.com/devices/tech/debug/dumpsys.html

[MaxAb]

I took bugreports with ADB tool via USB, so it dumped running services and everything else what dumpsys dumps.

[barah · Accepted solution]

i face the same problem so i downgrade to android 6 untill they update nogute and get rid from this problem 

[MaxAb]

Thanks @mohbarah, I would do that, but since there is no official way to downgrade - it may void the device warranty, so I won't.

[MaxAb]

Yesterday, i took away SIM card, so its modem became switched off and i did not observe any restart after that, neither freeze during night. This just confirms my suspicion about QC modem software in this firmware version. My mobile carrier is Sonera 4G LTE. 

Earlier i've also observed weak signal for the LTE network as shown by the phone indicator in the places, but actually there is so strong coverage, that is another evidence about QC modem sw poornes.

I got another device restart in the evening, without SIM card and mobile network active, only on WiFi.

the tombstone was not created, the bugreport does not show any system crash before restart timestamps.

Decided to return device.