From 9d8993be2d9149bc8b3132dad030ff5960f5abcc Mon Sep 17 00:00:00 2001 From: Lv Zheng Date: Thu, 11 Jun 2015 13:21:32 +0800 Subject: [PATCH] ACPI / EC: Convert event handling work queue into loop style. During the period that a work queue is scheduled (queued up for run) but hasn't been run, second schedule_work() could fail. This may not lead to the loss of queries because QR_EC is always ensured to be submitted after the work queue has been in the running state. The event handling work queue can be changed into the loop style to allow us to control the code in a more flexible way: 1. Makes it possible to add event=0x00 termination condition in the loop. 2. Increases the thoughput of the QR_EC transactions as the 2nd+ QR_EC transactions may be handled in the same work item used for the 1st QR_EC transaction, thus the delay caused by the 2nd+ work item scheduling can be eliminated. Except the logging message changes and the throughput improvement, this patch is just a funcitonal no-op. Signed-off-by: Lv Zheng Tested-by: Gabriele Mazzotta Tested-by: Tigran Gabrielyan Tested-by: Adrien D Signed-off-by: Rafael J. Wysocki --- drivers/acpi/ec.c | 33 ++++++++++++++++++++++++--------- drivers/acpi/internal.h | 1 + 2 files changed, 25 insertions(+), 9 deletions(-) diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c index 0ce8b6e8c3e8..824f3e85023e 100644 --- a/drivers/acpi/ec.c +++ b/drivers/acpi/ec.c @@ -384,7 +384,9 @@ static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec) static void acpi_ec_submit_query(struct acpi_ec *ec) { if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) { - ec_dbg_req("Event started"); + ec_dbg_evt("Command(%s) submitted/blocked", + acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY)); + ec->nr_pending_queries++; schedule_work(&ec->work); } } @@ -393,7 +395,8 @@ static void acpi_ec_complete_query(struct acpi_ec *ec) { if (test_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) { clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags); - ec_dbg_req("Event stopped"); + ec_dbg_evt("Command(%s) unblocked", + acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY)); } } @@ -460,8 +463,8 @@ static void advance_transaction(struct acpi_ec *ec) if (t->rlen == t->ri) { ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE); if (t->command == ACPI_EC_COMMAND_QUERY) - ec_dbg_req("Command(%s) hardware completion", - acpi_ec_cmd_string(t->command)); + ec_dbg_evt("Command(%s) completed by hardware", + acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY)); wakeup = true; } } else @@ -479,8 +482,8 @@ static void advance_transaction(struct acpi_ec *ec) ec_transaction_transition(ec, ACPI_EC_COMMAND_POLL); t->rdata[t->ri++] = 0x00; ec_transaction_transition(ec, ACPI_EC_COMMAND_COMPLETE); - ec_dbg_req("Command(%s) software completion", - acpi_ec_cmd_string(t->command)); + ec_dbg_evt("Command(%s) completed by software", + acpi_ec_cmd_string(ACPI_EC_COMMAND_QUERY)); wakeup = true; } else if ((status & ACPI_EC_FLAG_IBF) == 0) { acpi_ec_write_cmd(ec, t->command); @@ -961,11 +964,23 @@ static int acpi_ec_query(struct acpi_ec *ec, u8 *data) return result; } -static void acpi_ec_gpe_poller(struct work_struct *work) +static void acpi_ec_event_handler(struct work_struct *work) { + unsigned long flags; struct acpi_ec *ec = container_of(work, struct acpi_ec, work); - acpi_ec_query(ec, NULL); + ec_dbg_evt("Event started"); + + spin_lock_irqsave(&ec->lock, flags); + while (ec->nr_pending_queries) { + spin_unlock_irqrestore(&ec->lock, flags); + (void)acpi_ec_query(ec, NULL); + spin_lock_irqsave(&ec->lock, flags); + ec->nr_pending_queries--; + } + spin_unlock_irqrestore(&ec->lock, flags); + + ec_dbg_evt("Event stopped"); } static u32 acpi_ec_gpe_handler(acpi_handle gpe_device, @@ -1040,7 +1055,7 @@ static struct acpi_ec *make_acpi_ec(void) init_waitqueue_head(&ec->wait); INIT_LIST_HEAD(&ec->list); spin_lock_init(&ec->lock); - INIT_WORK(&ec->work, acpi_ec_gpe_poller); + INIT_WORK(&ec->work, acpi_ec_event_handler); ec->timestamp = jiffies; return ec; } diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h index 61cb50674359..b09756abc6e8 100644 --- a/drivers/acpi/internal.h +++ b/drivers/acpi/internal.h @@ -139,6 +139,7 @@ struct acpi_ec { spinlock_t lock; struct work_struct work; unsigned long timestamp; + unsigned long nr_pending_queries; }; extern struct acpi_ec *first_ec;