Re: [PATCH v1] chrome/cros_ec: Handle events during suspend after resume completion

From: Tzung-Bi Shih
Date: Fri Apr 26 2024 - 00:37:36 EST


On Thu, Apr 25, 2024 at 02:37:11PM -0600, Karthikeyan Ramasubramanian wrote:
> On boards where EC IRQ is not wake capable, EC does not trigger IRQ to
> signal any non-wake events until EC receives host resume event.

The sentence looks irrelevant to the fix. Presumably, EC should send those
pending non-wake events after it receives host resume event.

> Commit 47ea0ddb1f56 ("platform/chrome: cros_ec_lpc: Separate host
> command and irq disable") separated enabling IRQ and sending resume
> event host command into early_resume and resume_complete stages
> respectively. This separation leads to host not handling certain events
> posted during a small time window between early_resume and
> resume_complete stages. This change moves handling all events that
> happened during suspend after sending host resume event.

The regression you see is probably not due to the "separation" but an unwanted
code reorder.

Before 47ea0ddb1f56[1], a resume is:
1) Enable IRQ.
2) Send resume event.
3) Handle pending events.


After 47ea0ddb1f56[2], a resume is:
1) Enable IRQ.
2) Handle pending events.
3) Send resume event.

If there are some more events pending between 2) and 3), they would be handled
further late.

[1]: https://elixir.bootlin.com/linux/v6.6/source/drivers/platform/chrome/cros_ec.c#L381
[2]: https://elixir.bootlin.com/linux/v6.7/source/drivers/platform/chrome/cros_ec.c#L438


I see what the patch tries to fix but the commit message makes less sense to
me. Please fix accordingly.