Re: [PATCH v3 0/5] ACPI / EC: Move the event handling out of the noirq stage

From: Rafael J. Wysocki
Date: Mon Sep 12 2016 - 17:53:55 EST

On Wednesday, August 03, 2016 04:01:09 PM Lv Zheng wrote:
> There is a known issue in the EC driver.
> 1. During the suspend/resume process, the EC driver is required to work
> even in the noirq stage. And currently the event handling is
> disabled/enabled in the noirq stage.
> 2. Unfortunately, the EC driver only implements the polling mode for
> handling the transactions, and is not prepared to handle events in the
> polling mode.
> The result of the above conflict is: if an SCI_EVT is indicated during the
> noirq stage (especially after resuming), the EC driver is not able to
> detect the SCI_EVT unless:
> 1. GPE STS not cleared: When the GPE is enabled, advance_transaction() will
> be invoked to poll SCI_EVT.
> 2. EC transaction occurred: When an EC transaction ocurred,
> advance_transaction() will be invoked in the
> polling mode.
> If an SCI_EVT ocurred during noirq stage and the above 2 triggering sources
> cannot handle it, then a problem could be seen by the users:
> If SCI_EVT is left set after resuming and there is still no EC
> transactions, this event cannot be handled.
> This patchset tries to disable/enable the event handling out of the noirq
> stage to fix this issue.
> Though it is always correct to enable the event handling in a later stage
> during resuming as long as the event won't be lost, it may not be correct
> to disable the event handling in an earlier stage during suspending. This
> patchset thus put a boot parameter for the suspending part tuning in order
> to be able to respond to the possible regressions.
> Since the event handling is disabled for a longer period during
> suspend/resume, this patchset can also tune the suspend/resume speed
> faster.
> Lv Zheng (5):
> ACPI / EC: Add EC_FLAGS_QUERY_ENABLED to reveal a hidden logic
> ACPI / EC: Fix an issue that SCI_EVT cannot be detected after event
> is enabled
> ACPI / EC: Add PM operations to improve event handling for resume
> process
> ACPI / EC: Add PM operations to improve event handling for suspend
> process
> ACPI / EC: Enable event freeze mode to improve event handling
> efficiency for suspend process

Wholes series applied.