From c793570d8725e44b64dbe466eb8ecda34c5eb8ac Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 23 Nov 2021 19:43:05 +0100 Subject: ACPI: EC: Avoid queuing unnecessary work in acpi_ec_submit_event() Notice that it is not necessary to queue up the event work again if the while () loop in acpi_ec_event_handler() is still running which is the case if nr_pending_queries is greater than 0 at the beginning of acpi_ec_submit_event() and modify the code to avoid doing that. While at it, rename nr_pending_queries in struct acpi_ec to events_to_process which actually matches the role of that field and change its data type to unsigned int which is sufficient. No expected functional impact. Signed-off-by: Rafael J. Wysocki --- drivers/acpi/ec.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) (limited to 'drivers/acpi/ec.c') diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c index 473b1d8617b5..d578f41410ef 100644 --- a/drivers/acpi/ec.c +++ b/drivers/acpi/ec.c @@ -453,7 +453,16 @@ static bool acpi_ec_submit_event(struct acpi_ec *ec) if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) { ec_dbg_evt("Command(%s) submitted/blocked", acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY)); - ec->nr_pending_queries++; + /* + * If events_to_process is greqter than 0 at this point, the + * while () loop in acpi_ec_event_handler() is still running + * and incrementing events_to_process will cause it to invoke + * acpi_ec_submit_query() once more, so it is not necessary to + * queue up the event work to start the same loop again. + */ + if (ec->events_to_process++ > 0) + return true; + ec->events_in_progress++; return queue_work(ec_wq, &ec->work); } @@ -665,7 +674,7 @@ static bool advance_transaction(struct acpi_ec *ec, bool interrupt) */ if (!t || !(t->flags & ACPI_EC_COMMAND_POLL)) { if (ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT && - (!ec->nr_pending_queries || + (!ec->events_to_process || test_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags))) { clear_bit(EC_FLAGS_QUERY_GUARDING, &ec->flags); acpi_ec_close_event(ec); @@ -1223,13 +1232,13 @@ static void acpi_ec_event_handler(struct work_struct *work) spin_lock_irq(&ec->lock); - while (ec->nr_pending_queries) { + while (ec->events_to_process) { spin_unlock_irq(&ec->lock); acpi_ec_submit_query(ec); spin_lock_irq(&ec->lock); - ec->nr_pending_queries--; + ec->events_to_process--; } /* -- cgit v1.2.3