i.MX6q Android 4.3 Kernel crash / unstable at 1.2Ghz (and 996Mhz).

[anthonydefeo]

I am running the android_jb4.3_1.1.0 image on a Freescale MCIMX6Q-SDB board.

The system is running at 1080p resolution.

I have upped the frequency to 1.2Ghz by blowing the SPEED_GRADING fuse:

"imxotp blow --force 4 0x2b0302"

and setting the cpu frequency to max from android console:

echo userspace > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor; echo 1200000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed;

At this speed, the system is unstable and the kernel will randomly crash with various oops messages (undefined instruction, unable to handle kernel paging request, unable to handle kernel null pointer reference, etc).

I am also running a build of android from source on multiple wandboard/technexion imx6q boards, and they all fail in the same way (some of them even fail at 996Mhz).

The system will crash randomly, but It seems to happen more often from the android settings->Data Usage screen.

All of the boards appear to be stable at 792Mhz.

We are developing a commercial product based on the wandboard/technexion, and this is a show stopper for us.

Any help or ideas would be greatly appreciated!

Thanks,

Tony DeFeo

Incredible Technologies, Inc.

[igorpadykov]

Hi Anthony

this speed fuse is blown on Freescale factory

(but not customer), after passing 1.2 Ghz qualification tests

and have special marking, for example MCIMX6Q5EYM12AC.

Best regards

chip

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[anthonydefeo]

Thanks for the info, I didn't realize that the part was only rated at 1Ghz!

However, I am still having similar issues at 996Mhz, and the failure mode appears to be the same as when I run the part at 1.2Ghz except that it happens much more frequently at 1.2Ghz.

When I run the part at 792Mhz, I don't see the failure.

Any other ideas or help would be appreciated!

Thanks,

Tony

[jiujinhong]

Hi Anthony,

did you fix this issue?

[igorpadykov]

Could you try linux ?