From c33676aa48249b007d55198dc8348cd117e3d8cc Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 23 Nov 2021 19:44:46 +0100 Subject: ACPI: EC: Make the event work state machine visible The EC driver uses a relatively simple state machine for the event work handling, but it is not really straightforward to figure out. The states are as follows: "Ready": The event handling work can be submitted. In this state, the EC_FLAGS_QUERY_PENDING flag is clear. "In progress": The event handling work is pending or is being processed. It cannot be submitted again. In ths state, the EC_FLAGS_QUERY_PENDING flag is set and both the events_to_process count is nonzero and the EC_FLAGS_QUERY_GUARDING flag is clear. "Complete": The event handling work has been completed, but it still cannot be submitted again. In ths state, the EC_FLAGS_QUERY_PENDING flag is set and the events_to_process count is zero or the EC_FLAGS_QUERY_GUARDING flag is set. The state changes from "Ready" to "In progress" when new event is detected by advance_transaction() and acpi_ec_submit_event() is called by it. Next, the state can change from "In progress" directly to "Ready" in the following situations: * ec_event_clearing is ACPI_EC_EVT_TIMING_STATUS and the state of an ACPI_EC_COMMAND_QUERY transaction becomes ACPI_EC_COMMAND_POLL. * ec_event_clearing is ACPI_EC_EVT_TIMING_QUERY and the state of an ACPI_EC_COMMAND_QUERY transaction becomes ACPI_EC_COMMAND_COMPLETE. * ec_event_clearing is either ACPI_EC_EVT_TIMING_STATUS or ACPI_EC_EVT_TIMING_QUERY and there are no more events to process (ie. ec->events_to_process becomes 0). If ec_event_clearing is ACPI_EC_EVT_TIMING_EVENT, however, the state must change from "In progress" to "Complete" before it can change to "Ready". The changes from "In progress" to "Complete" in that case occur in the following situations: * The state of an ACPI_EC_COMMAND_QUERY transaction becomes ACPI_EC_COMMAND_COMPLETE. * There are no more events to process (ie. ec->events_to_process becomes 0). Finally, the state changes from "Complete" to "Ready" when advance_transaction() is invoked when the state is "Complete" and the state of the current transaction is not ACPI_EC_COMMAND_POLL. To make this state machine visible in the code, add a new event_state field to struct acpi_ec and modify the code to use it istead the EC_FLAGS_QUERY_PENDING and EC_FLAGS_QUERY_GUARDING flags. Signed-off-by: Rafael J. Wysocki --- drivers/acpi/internal.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'drivers/acpi/internal.h') diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h index de546be3bc6a..1db3a2f81763 100644 --- a/drivers/acpi/internal.h +++ b/drivers/acpi/internal.h @@ -166,6 +166,13 @@ static inline void acpi_early_processor_osc(void) {} /* -------------------------------------------------------------------------- Embedded Controller -------------------------------------------------------------------------- */ + +enum acpi_ec_event_state { + EC_EVENT_READY = 0, /* Event work can be submitted */ + EC_EVENT_IN_PROGRESS, /* Event work is pending or being processed */ + EC_EVENT_COMPLETE, /* Event work processing has completed */ +}; + struct acpi_ec { acpi_handle handle; int gpe; @@ -182,6 +189,7 @@ struct acpi_ec { spinlock_t lock; struct work_struct work; unsigned long timestamp; + enum acpi_ec_event_state event_state; unsigned int events_to_process; unsigned int events_in_progress; unsigned int queries_in_progress; -- cgit v1.2.3-59-g8ed1b