SMP BUG.

[vDorst]

The Amlogic Kernel has a SMP bug. Depenting on the timing of some code, the hardware will lockup. Also the kernel gives a warning. See in bootlog: https://gist.github.com/vDorst/5472710#file-gistfile1-txt-L444

The lockup happens more with the linaro armhf compiler. It seems to me that is a serious issue.

[waschmi]

Not beeing able to code, I don't really know what I'm talking about but chances are the responsible file is: arch/arm/plat-meson/include/plat/io.h

[vDorst]

It is a bug in cpu freqscaler. Simple solution is to disable it. But it would be great to fix it for better energy efficiency.

[waschmi]

The most stable configuration for my tablet seems to be: In Kernel CMDLINE a9_clk_max=13200000000 CONFIG_DEFAULT_DEADLINE=y CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMANDE=y

This gave me a proper cpu scaling over a longer period of time. It's seems a powersaving state could trigger a 2nd cpu lockup, sometimes.

[vDorst]

Ok, thanks for the info. Tuesday I receive a JTAG dongle. I hope that gives me more information when it goes wrong.

[xlazom00]

If I disable SMP and NO_HZ my kernel never bootup http://pastebin.com/G87fqGTL

[vDorst]

I seems to boot ok. The kernel expects a rootfs on the SDcard with fstype ext4. See boot log line 23. "[ 0.000000] Kernel command line: console=ttyS0,115200n8 nohlt noinitrd rootwait root=/dev/cardblksd2 rootfstype=ext4 rw mem=1024M a9_clk_max=1112000000 mac=ac:db:da:02:42:3e verhw=MX_NORMAL"

[xlazom00]

I know If I enable SMP and NO_HZ all boot up "fine" if I am lucky. I post this log for debug purpose in case you are debugging kernel boot up with JTAG

[xlazom00]

it looks like old kernel is much more stable than this new one http://www.slatedroid.com/topic/38070-ubuntu-1210-quantal-armhf-for-elf-ii/ http://www.slatedroid.com/topic/37745-elf-ii-kernel-development/ I think that my ATV1200 came with 3.0.6

[Lupul]

vDorst what JTAG dongle have you purchased ?

[vDorst]

I am using a FTDI FT2232H based JTAG dongle, the Olimex - ARM-USB-TINY-H.