Hello Marc,



thanks for reviewing.



On Sun, 15 Mar 2026, Marc Dietrich wrote:

> Reading out the battery info during boot takes some time as far as I

> remember, but I haven't tested your patches yet. Is the use of sync

> writes really required in order to realize a clean suspend?



You're right, I worked out some math on this, and I agree that the sync

conversion isn't strictly necessary.



The worst case with async writes during suspend is a reply arriving

after work has been cancelled. That reply would just be lost, and since

the poller refreshes everything on resume, there's no corruption or

crash — just one missed update.



The sync approach does avoid that window, but the cost is structural:

the battery metadata init serializes N queries, so the boot-time wall

time goes from roughly one EC round-trip to N * T_rt. With N = 3

(MANUFACTURER, MODEL, TYPE), the relative overhead is always 2x

regardless of how fast the EC is. Without hardware to measure T_rt

I can't tell whether that's 100ms or 2s of added latency, but either

way it's a cost with no real safety benefit.



> Are you able to test the change on real hardware?



Unfortunately I don't have access to Tegra 2 hardware, so this has

only been build-tested and reviewed by inspection. I'd appreciate it

if you or someone on the ac100 list could validate the v2 on a real

device.



If you think the lost-reply window during suspend is benign, I'd

prefer to drop patch 1 and send a v2 with just the PM hooks on top

of the existing async flow. Otherwise, I'm happy to keep the sync

conversion as-is.





Best regards,

Gustavo Arantes