05-24-2020, 04:03 PM
(05-17-2020, 04:01 PM)Dendrocalamus64 Wrote: Yes, CONFIG_MAGIC_SYSRQ is enabled, but it's occasionally useful so I don't want to turn it off if I don't have to.
Dendrocalamus64, sysrq is not enabled by default on MrFixIT's kernel:
CONFIG_MAGIC_SYSRQ=y
CONFIG_MAGIC_SYSRQ_DEFAULT_ENABLE=0
You did not run into garbage SYSRQs anyway. The cause of your kernel crashes is hard to debug. Perhaps install MrFixIT's latest kernel 4.4.222 or even better move to a distribution with a 5.X kernel. The 5.X kernels are rock-stable on the Pinebook Pro.
(05-15-2020, 09:52 AM)manawyrm Wrote: Manjaro have disabled SYSRQs in our kernel for this reason.
More recent kernels, such as Manjaros 5.X kernel, have an additonal option CONFIG_MAGIC_SYSRQ_SERIAL. I'm surprised Manjaro has completely disabled SYSRQ while not making use of CONFIG_MAGIC_SYSRQ_SERIAL=0.
(05-18-2020, 12:00 AM)manawyrm Wrote: SYSRQs can also be issued over the UART. And the UART on the PBP is also being used as the headphone jack for audio.
There is significant (~3Vpp) Crosstalk between the audio and UART lines. This is a hardware issue.
This is highly interesting but why is there cross-talk even when there is no headset plugged in? Shouldn't the audio line be "idle"?
