Odroid-C2 solid green screen on "echo c > /proc/sysrq-trigger" on Arch 4.16/4.17rc6

Swabey, Matthew A maswabey at purdue.edu
Sat May 26 15:20:59 PDT 2018


Well, if it is triggered on watchdog reboot, but not normal power-on or reboot then it has to be either the firmware, u-boot or the kernel not reconfiguring something. 

I don't know what the difference is between a watchdog reset and a normal boot though which would cause the change. Any hints before I go digging with a JTAG adapter through the SCP or SoC registers? (Thinking of dumping and diff'ing to see what changed.)

Matt

Dr. Matthew Swabey - Director 
Bechtel Innovation Design Center - Purdue University
room: BIDC 225      phone: +1-765-494-8655

-----Original Message-----
From: Michał Zegan [mailto:webczat_200 at poczta.onet.pl] 
Sent: Saturday, May 26, 2018 4:50 AM
To: Neil Armstrong <narmstrong at baylibre.com>; Swabey, Matthew A <maswabey at purdue.edu>; Tony McKahan <tonymckahan at gmail.com>
Cc: linux-amlogic at lists.infradead.org
Subject: Re: Odroid-C2 solid green screen on "echo c > /proc/sysrq-trigger" on Arch 4.16/4.17rc6

What about the *kernel* resetting at boot?

W dniu 26.05.2018 o 10:33, Neil Armstrong pisze:
> Hi,
> 
> I'm sorry to disappoint you, but with the HW watchdog, we *can't* execute any code from Linux when the watchdoog resets the system.
> We could eventually add some code in U-Boot to disable the HDMI output, but U-boot is not the first code executed, you will still see the green screen.
> You may need to contact Hardkernel to see if they can update the BL* binaries to include such reset.
> 
> Neil
> 
> On 26/05/2018 05:49, Swabey, Matthew A wrote:
>> Can also confirm green screen on watchdog reboot from "echo c > /proc/sysrq-trigger" for Armbian 5.44 with linux-u-boot-odroidc2-next version 2018.03.
>>
>> This is in addition to the Armbian bug where shutdown -r now doesn’t reboot the system, just either freezes or powers down. Supposed to be fixed on 2018.03 but not working for me.
>>
>> Matthew
>>
>> Dr. Matthew Swabey - Director
>> Bechtel Innovation Design Center - Purdue University
>> room: BIDC 225      phone: +1-765-494-8655
>>
>> -----Original Message-----
>> From: linux-amlogic 
>> [mailto:linux-amlogic-bounces at lists.infradead.org] On Behalf Of 
>> Swabey, Matthew A
>> Sent: Friday, May 25, 2018 10:37 PM
>> To: Tony McKahan <tonymckahan at gmail.com>; Neil Armstrong 
>> <narmstrong at baylibre.com>
>> Cc: linux-amlogic at lists.infradead.org
>> Subject: RE: Odroid-C2 solid green screen on "echo c > 
>> /proc/sysrq-trigger" on Arch 4.16/4.17rc6
>>
>> I just had a look at the Arch linux PKGBUILD for the uboot package I am using, and it is mainline 2017.07. So I am using the mainline uboot, just a bit older.
>>
>> I’ll give Armbian a try – is it the distro wit1h the most development so far? (Other than the 3.14.x releases which I would prefer not to use for now).
>>
>> Matthew
>>
>> Dr. Matthew Swabey - Director
>> Bechtel Innovation Design Center - Purdue University
>> room: BIDC 225      phone: +1-765-494-8655
>>
>> From: Tony McKahan [mailto:tonymckahan at gmail.com]
>> Sent: Friday, May 25, 2018 3:46 PM
>> To: Neil Armstrong <narmstrong at baylibre.com>
>> Cc: Swabey, Matthew A <maswabey at purdue.edu>; 
>> linux-amlogic at lists.infradead.org
>> Subject: Re: Odroid-C2 solid green screen on "echo c > 
>> /proc/sysrq-trigger" on Arch 4.16/4.17rc6
>>
>> Hello Neil, Matt,
>>
>> Change to 2018.03 is in Armbian's development branch, just waiting to be rolled into the master.  I don't have this particular board for testing, but it should be updated soon.
>>
>> On Fri, May 25, 2018, 3:57 AM Neil Armstrong <mailto:narmstrong at baylibre.com> wrote:
>> Hi,
>>
>> On 25/05/2018 04:19, Swabey, Matthew A wrote:
>>> Odroid-C2 solid green screen on echo c > /proc/sysrq-trigger on Arch 
>>> Linux mainline 4.16/4.17rc6 Using lightdm on xorg fb. No mali, utgard or odroid specific framebuffers. However it seems to happen on them too.
>>>
>>> Steps to reproduce:
>>> 1. Boot
>>> 2. Echo c > /proc/sysrq-trigger with watchdog set. Or trigger the watchdog another way, i.e. watchdogd or system.
>>> 3. Watchdog causes reboot
>>> 4. Boots with screen solid green, see photo here: 
>>> https://photos.app.goo.gl/9VyiweNAIMD07VSM2
>>>        a. No error messages visible, see attached log file bundles 
>>> containing dmesg, journalctl, package list, Xorg.0.log
>>>        b. Linux-aarch64 is 4.16
>>>        c. Linux-aarch64-rc is 4.17rc6 5. Reboot - screen back to 
>>> normal and working
>> Well, since screen goes back to normal means there is no bug on the kernel side.
>>
>> This is caused by Amlogic's U-Boot.
>> The HW watchdog does a complete SoC reset, we cannot execute any code from kernel when the watchdog wakes up.
>>
>> Please report this to Armbian and ask them to use Mainline U-Boot, this won't happen anymore.
>>
>> Neil
>>
>>>
>>> Thought - something about the way to trigger this reset isn't working, or a race condition is present which is being more reliably triggered? Perhaps in the dma controller or the HDMI?
>>>
>>> Any help to track this bug down would be very helpful, or someone else who would be interested? I can't figure out where in the stack the problem is occurring, but I guess it is the bootloader.
>>>
>>> Thanks,
>>>
>>> Matthew
>>>
>>>
>>>
>>> _______________________________________________
>>> linux-amlogic mailing list
>>> mailto:linux-amlogic at lists.infradead.org
>>> http://lists.infradead.org/mailman/listinfo/linux-amlogic
>>>
>>
>>
>> _______________________________________________
>> linux-amlogic mailing list
>> mailto:linux-amlogic at lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-amlogic
>> _______________________________________________
>> linux-amlogic mailing list
>> linux-amlogic at lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-amlogic
>>
> 
> 
> _______________________________________________
> linux-amlogic mailing list
> linux-amlogic at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-amlogic
> 



More information about the linux-amlogic mailing list