m1n1: tps6598x_powerup failed for /arm-io/i2c0/hpmBusManager/hpm1

(Split off from AsahiLinux/m1n1#97)

On my MacBook Pro, which has run other kernels and boot loaders but is currently loading vanilla m1n1, commit c2c6da3, directly from iBoot, I occasionally see messages like:

TTY> i2c: want to read 1 bytes from addr 63 but can only read 0
TTY> usb: tps6598x_powerup failed for /arm-io/i2c0/hpmBusManager/hpm1.
TTY> usb: failed to init hpm1

I’ve been unable to reproduce this at will. I’ve never seen the problem except when the power supply was connected to either one of the USB-C ports. However, it’s always hpm1 that’s mentioned in the error message.

In AsahiLinux/m1n1#72, @jannau mentions he had to add delays to the i2c code in order to avoid similar-sounding issues. Do you want me to try doing that?

About this issue

Original URL
State: open
Created 3 years ago
Comments: 23 (20 by maintainers)

Commits related to this issue

i2c: Increase low-level timeouts to 50ms. Hopefully this will cover all corner cases of the Ace2s being slow. Issue: #101 Signed-off-by: Hector Martin <marcan@marcan.st> — committed to AsahiLinux/m1n1 by marcan 2 years ago

Most upvoted comments

Repro’d fairly reliably with the AV adapter.

marcan on Feb 6, 2022

I just did 25 boots, long-pressing the power-button between each, and got 6 failures. In four of the failure cases, no ttyACM* interface showed up; in the other two, it did, and five subsequent chainloads were successful.

My gut says “race condition”.

alyssarosenzweig on Aug 24, 2021