Craig Lamparter

I take that back, it worked once. I'll play the high/low game and see if I can isolate which kernel commit broke ttyACM on PiZero2w using gpsd.

Bug was introduced in this commit (kernel went from 6.1.x to 6.6.x) ``` kernel: Bump to 6.6.16 kernel from next branch popcornmix committed on Feb 8 e632362b0399b4ce331aacd9386685bc60938ab7 ```

update: 6.12.20+rpt-rpi-v7 is working edit: sorry, false negative, it's crashing like the others (gps wasn't locked yet)

Problem exists with 6.12.25+rpt-rpi-v7 . "gpsd -n -b /dev/ttyACM1", or even just "gpsd /dev/ttyACM1" as a mortal user instantly locks up a PiZero2W. no hdmi, no wifi, no bluetooth, sd...

Confirming kernel bug was introduced between 6.1.x series and 6.6.x series. When gpsd reads from ttyACM1, the PiZero2W (Pi5 is fine) locks up, green LED blinks 17 times (once per...

> Are you able to reproduce the lockup without a HAM radio costing ~£1500? Not yet. a cheap ublox gps uses ttyACM and seems to work, it may have locked...

Reproduced on Pi3A+ and Pi3B+ (BCM2835 seems to be the common factor).

> Have you tried with `dtoverlay=dwc2,dr_mode=host` in config.txt? That will cause the Pi to use a slower but more battle-hardened USB driver. Added - it's working!! Use this for all...

> Can someone look at this file and suggest some changes to explain the fix? > > https://gitlab.com/gpsd/gpsd/-/blob/master/INSTALL.adoc?ref_type=heads _If your Raspberry Pi locks up as gpsd starts, particularly on PiZero2/3B+/3A+,...

Older PIthos from Kde Neon, Ubuntu 22.04, for reference, functioning normally, no hangs/lag, decorations, wm icon, etc. I switched back to this. Works great!