168 lines
5.2 KiB
Diff
168 lines
5.2 KiB
Diff
From: Lv Zheng <lv.zheng@intel.com>
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Date: Fri, 20 Jan 2017 16:42:48 +0800
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Subject: ACPI / EC: Use busy polling mode when GPE is not enabled
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Origin: https://git.kernel.org/linus/c3a696b6e8f8f75f9f75e556a9f9f6472eae2655
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Bug: https://bugzilla.kernel.org/show_bug.cgi?id=191561
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Bug-Debian: https://bugs.debian.org/846792
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When GPE is not enabled, it is not efficient to use the wait polling mode
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as it introduces an unexpected scheduler delay.
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So before the GPE handler is installed, this patch uses busy polling mode
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for all EC(s) and the logic can be applied to non boot EC(s) during the
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suspend/resume process.
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Link: https://bugzilla.kernel.org/show_bug.cgi?id=191561
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Tested-by: Jakobus Schurz <jakobus.schurz@gmail.com>
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Tested-by: Chen Yu <yu.c.chen@intel.com>
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Signed-off-by: Lv Zheng <lv.zheng@intel.com>
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Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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---
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drivers/acpi/ec.c | 62 ++++++++++++++++++++++++-------------------------
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drivers/acpi/internal.h | 4 ++--
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2 files changed, 32 insertions(+), 34 deletions(-)
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diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
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index 6a32cd4ec9da..c24235d8fb52 100644
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--- a/drivers/acpi/ec.c
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+++ b/drivers/acpi/ec.c
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@@ -704,12 +704,12 @@ static void start_transaction(struct acpi_ec *ec)
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static int ec_guard(struct acpi_ec *ec)
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{
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- unsigned long guard = usecs_to_jiffies(ec_polling_guard);
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+ unsigned long guard = usecs_to_jiffies(ec->polling_guard);
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unsigned long timeout = ec->timestamp + guard;
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/* Ensure guarding period before polling EC status */
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do {
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- if (ec_busy_polling) {
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+ if (ec->busy_polling) {
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/* Perform busy polling */
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if (ec_transaction_completed(ec))
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return 0;
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@@ -973,6 +973,28 @@ static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)
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spin_unlock_irqrestore(&ec->lock, flags);
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}
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+static void acpi_ec_enter_noirq(struct acpi_ec *ec)
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+{
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+ unsigned long flags;
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+
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+ spin_lock_irqsave(&ec->lock, flags);
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+ ec->busy_polling = true;
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+ ec->polling_guard = 0;
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+ ec_log_drv("interrupt blocked");
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+ spin_unlock_irqrestore(&ec->lock, flags);
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+}
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+
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+static void acpi_ec_leave_noirq(struct acpi_ec *ec)
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+{
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+ unsigned long flags;
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+
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+ spin_lock_irqsave(&ec->lock, flags);
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+ ec->busy_polling = ec_busy_polling;
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+ ec->polling_guard = ec_polling_guard;
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+ ec_log_drv("interrupt unblocked");
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+ spin_unlock_irqrestore(&ec->lock, flags);
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+}
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+
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void acpi_ec_block_transactions(void)
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{
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struct acpi_ec *ec = first_ec;
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@@ -1253,7 +1275,7 @@ acpi_ec_space_handler(u32 function, acpi_physical_address address,
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if (function != ACPI_READ && function != ACPI_WRITE)
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return AE_BAD_PARAMETER;
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- if (ec_busy_polling || bits > 8)
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+ if (ec->busy_polling || bits > 8)
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acpi_ec_burst_enable(ec);
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for (i = 0; i < bytes; ++i, ++address, ++value)
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@@ -1261,7 +1283,7 @@ acpi_ec_space_handler(u32 function, acpi_physical_address address,
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acpi_ec_read(ec, address, value) :
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acpi_ec_write(ec, address, *value);
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- if (ec_busy_polling || bits > 8)
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+ if (ec->busy_polling || bits > 8)
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acpi_ec_burst_disable(ec);
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switch (result) {
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@@ -1304,6 +1326,8 @@ static struct acpi_ec *acpi_ec_alloc(void)
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spin_lock_init(&ec->lock);
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INIT_WORK(&ec->work, acpi_ec_event_handler);
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ec->timestamp = jiffies;
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+ ec->busy_polling = true;
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+ ec->polling_guard = 0;
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return ec;
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}
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@@ -1365,6 +1389,7 @@ static int ec_install_handlers(struct acpi_ec *ec, bool handle_events)
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acpi_ec_start(ec, false);
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if (!test_bit(EC_FLAGS_EC_HANDLER_INSTALLED, &ec->flags)) {
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+ acpi_ec_enter_noirq(ec);
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status = acpi_install_address_space_handler(ec->handle,
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ACPI_ADR_SPACE_EC,
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&acpi_ec_space_handler,
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@@ -1404,6 +1429,7 @@ static int ec_install_handlers(struct acpi_ec *ec, bool handle_events)
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/* This is not fatal as we can poll EC events */
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if (ACPI_SUCCESS(status)) {
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set_bit(EC_FLAGS_GPE_HANDLER_INSTALLED, &ec->flags);
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+ acpi_ec_leave_noirq(ec);
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if (test_bit(EC_FLAGS_STARTED, &ec->flags) &&
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ec->reference_count >= 1)
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acpi_ec_enable_gpe(ec, true);
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@@ -1786,34 +1812,6 @@ int __init acpi_ec_ecdt_probe(void)
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}
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#ifdef CONFIG_PM_SLEEP
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-static void acpi_ec_enter_noirq(struct acpi_ec *ec)
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-{
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- unsigned long flags;
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-
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- if (ec == first_ec) {
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- spin_lock_irqsave(&ec->lock, flags);
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- ec->saved_busy_polling = ec_busy_polling;
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- ec->saved_polling_guard = ec_polling_guard;
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- ec_busy_polling = true;
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- ec_polling_guard = 0;
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- ec_log_drv("interrupt blocked");
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- spin_unlock_irqrestore(&ec->lock, flags);
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- }
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-}
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-
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-static void acpi_ec_leave_noirq(struct acpi_ec *ec)
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-{
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- unsigned long flags;
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-
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- if (ec == first_ec) {
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- spin_lock_irqsave(&ec->lock, flags);
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- ec_busy_polling = ec->saved_busy_polling;
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- ec_polling_guard = ec->saved_polling_guard;
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- ec_log_drv("interrupt unblocked");
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- spin_unlock_irqrestore(&ec->lock, flags);
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- }
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-}
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-
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static int acpi_ec_suspend_noirq(struct device *dev)
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{
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struct acpi_ec *ec =
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diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
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index 0c452265c111..219b90bc0922 100644
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--- a/drivers/acpi/internal.h
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+++ b/drivers/acpi/internal.h
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@@ -172,8 +172,8 @@ struct acpi_ec {
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struct work_struct work;
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unsigned long timestamp;
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unsigned long nr_pending_queries;
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- bool saved_busy_polling;
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- unsigned int saved_polling_guard;
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+ bool busy_polling;
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+ unsigned int polling_guard;
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};
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extern struct acpi_ec *first_ec;
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--
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2.11.0
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