0003693: Some F&S boards freeze after some time

ID	Project	Category	View Status	Date Submitted	Last Update

0003693	fsimx_Linux	Kernel	public	2019-01-25 17:07	2019-01-25 17:24

Reporter	Keller	Assigned To
Priority	normal	Severity	major	Reproducibility	sometimes
Status	resolved	Resolution	fixed
Product Version	fsimx6sx-V2.0
Target Version	fsimx6-V3.1	Fixed in Version	fsimx6-V3.1

Summary	0003693: Some F&S boards freeze after some time
Description	Some F&S boards, especially on i.MX6SX, work fine when booting, but then suddenly freeze. Sometimes this happens immediately after booting, sometimes they work for some minutes and then freeze. The effect seems to happen when the board goes to a lower CPU frequency. If the board is held at high speed, for example by setting the CPU frequency scaling governor to "performance", then everything works fine.
Steps To Reproduce	Use an affected board, start and wait. After a few seconds after booting, the board stops reacting to input on the command line. Call make menuconfig for the kernel and go to "CPU Power Management" -> "CPU Frequency scaling" -> "Default CPUFreq governor" and set it to "performance". Save config, recompile kernel and start this kernel on the board. Now everything will work. Remark: Sometimes the board works for about 10 minutes and then freezes. If this is the case, it is sufficient to set the governor at runtime: echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling-governor Then the board will also work indefinitely.

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