[next] Odroid XU3 easily over-heats

[next] Odroid XU3 easily over-heats

[Krzysztof Kozlowski]

Hi all,

With recent addition of cpufreq-dt support to Exynos5422
it is very easy to over-heat the Odroid XU3 leading to critical shutdown:
[  132.622032] thermal thermal_zone3: critical temperature reached(121 C),shutting down


Reproduction:
0. next-20160212 (with recent fix for OPP from Viresh)
1. multi_v7 (on exynos defconfig there is no cpufreq for Exynos5422)
2. Run following test script:
https://github.com/krzk/tools/blob/master/tests/odroid-xu3-cpu-mmc-stress.sh

(the script essentially does only "cat /dev/mmcblk0p2 | gzip -c > /dev/null" for each CPU)

Observe, just before shutdown:
/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq:1300000
/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq:200000
/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_transition_latency:154000
/sys/devices/system/cpu/cpu0/cpufreq/related_cpus:0 1 2 3
/sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies:200000 300000 400000 500000 600000 700000 800000 900000 1000000 1100000 1200000 1300000 
/sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors:ondemand performance 
/sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq:1300000
/sys/devices/system/cpu/cpu0/cpufreq/scaling_driver:cpufreq-dt
/sys/devices/system/cpu/cpu0/cpufreq/scaling_governor:ondemand
/sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq:1300000
/sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq:200000
/sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed:<unsupported>

/sys/class/thermal/thermal_zone0/temp:90000
/sys/class/thermal/thermal_zone1/temp:98000
/sys/class/thermal/thermal_zone2/temp:113000
/sys/class/thermal/thermal_zone3/temp:119000
/sys/class/thermal/thermal_zone4/temp:81000

/sys/class/thermal/cooling_device0/cur_state:3
/sys/class/thermal/cooling_device0/max_state:3
/sys/class/thermal/cooling_device0/type:pwm-fan

Fan is working but shutdown is immediate.

What about cpufreq as cooling device? Probably that part
is missing now, right?

Best regards,
Krzysztof

[next] Odroid XU3 easily over-heats

[Viresh Kumar]

On 14-02-16, 15:06, Krzysztof Kozlowski wrote:
> Hi all,
> 
> With recent addition of cpufreq-dt support to Exynos5422
> it is very easy to over-heat the Odroid XU3 leading to critical shutdown:

How were OPPs passed earlier? I failed to see them in kernel somehow.
You must have been using opp-v1 earlier, right?

You used boost-freqs then? You used cpufreq as a cooling device then?

> What about cpufreq as cooling device? Probably that part
> is missing now, right?

Maybe, how was that earlier though ?

-- 
viresh

[next] Odroid XU3 easily over-heats

[Krzysztof Kozlowski]

On 15.02.2016 14:28, Viresh Kumar wrote:
> On 14-02-16, 15:06, Krzysztof Kozlowski wrote:
>> Hi all,
>>
>> With recent addition of cpufreq-dt support to Exynos5422
>> it is very easy to over-heat the Odroid XU3 leading to critical shutdown:
> 
> How were OPPs passed earlier? I failed to see them in kernel somehow.
> You must have been using opp-v1 earlier, right?

Till now there was no support for cpufreq for Exynos542x. For some time
Bartlomiej was developing these patches - using opp-v1 at beginning. I
don't know whether he encountered this before.

> 
> You used boost-freqs then? You used cpufreq as a cooling device then?
> 
>> What about cpufreq as cooling device? Probably that part
>> is missing now, right?
> 
> Maybe, how was that earlier though ?

Bootloader initialized frequency and regulators to some safe defaults. I
think the voltage set by uboot is 1 V (for big and little) which
corresponds to ~800 MHz of frequency (I don't know the exact frequency
because it is hardcoded as divider value...).

However there was no cooling device except fan. This did not change. So
the only difference seems to be that now at critical shutdown moment it
operates at 1300 MHz / 1.275 V (little) and 1800 MHz / 1.250 V (big).

Best regards,
Krzysztof