From c2b46d679b30c5c0d7eb47a21085943242bdd8dc Mon Sep 17 00:00:00 2001 From: Lv Zheng Date: Wed, 3 Aug 2016 16:01:36 +0800 Subject: ACPI / EC: Add PM operations to improve event handling for resume process This patch makes 2 changes: 1. Restore old behavior Originally, EC driver stops handling both events and transactions in acpi_ec_block_transactions(), and restarts to handle transactions in acpi_ec_unblock_transactions_early(), restarts to handle both events and transactions in acpi_ec_unblock_transactions(). While currently, EC driver still stops handling both events and transactions in acpi_ec_block_transactions(), but restarts to handle both events and transactions in acpi_ec_unblock_transactions_early(). This patch tries to restore the old behavior by dropping __acpi_ec_enable_event() from acpi_unblock_transactions_early(). 2. Improve old behavior However this still cannot fix the real issue as both of the acpi_ec_unblock_xxx() functions are invoked in the noirq stage. Since the EC driver actually doesn't implement the event handling in the polling mode, re-enabling the event handling too early in the noirq stage could result in the problem that if there is no triggering source causing advance_transaction() to be invoked, pending SCI_EVT cannot be detected by the EC driver and _Qxx cannot be triggered. It actually makes sense to restart the event handling in any point during resuming after the noirq stage. Just like the boot stage where the event handling is enabled in .add(), this patch further moves acpi_ec_enable_event() to .resume(). After doing that, the following 2 functions can be combined: acpi_ec_unblock_transactions_early()/acpi_ec_unblock_transactions(). The differences of the event handling availability between the old behavior (this patch isn't applied) and the new behavior (this patch is applied) are as follows: !Applied Applied before suspend Y Y suspend before EC Y Y suspend after EC Y Y suspend_late Y Y suspend_noirq Y (actually N) Y (actually N) resume_noirq Y (actually N) Y (actually N) resume_late Y (actually N) Y (actually N) resume before EC Y (actually N) Y (actually N) resume after EC Y (actually N) Y after resume Y (actually N) Y Where "actually N" means if there is no triggering source, the EC driver is actually not able to notice the pending SCI_EVT occurred in the noirq stage. So we can clearly see that this patch has improved the situation. Signed-off-by: Lv Zheng Tested-by: Todd E Brandt Signed-off-by: Rafael J. Wysocki --- drivers/acpi/ec.c | 26 +++++++++++--------------- 1 file changed, 11 insertions(+), 15 deletions(-) (limited to 'drivers/acpi/ec.c') diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c index 79305bed4164..8d5444defd7e 100644 --- a/drivers/acpi/ec.c +++ b/drivers/acpi/ec.c @@ -909,8 +909,7 @@ static void acpi_ec_start(struct acpi_ec *ec, bool resuming) if (!resuming) { acpi_ec_submit_request(ec); ec_dbg_ref(ec, "Increase driver"); - } else - __acpi_ec_enable_event(ec); + } ec_log_drv("EC started"); } spin_unlock_irqrestore(&ec->lock, flags); @@ -965,19 +964,6 @@ void acpi_ec_block_transactions(void) } void acpi_ec_unblock_transactions(void) -{ - struct acpi_ec *ec = first_ec; - - if (!ec) - return; - - /* Allow transactions to be carried out again */ - acpi_ec_start(ec, true); - - acpi_ec_enable_event(ec); -} - -void acpi_ec_unblock_transactions_early(void) { /* * Allow transactions to happen again (this function is called from @@ -1706,10 +1692,20 @@ static int acpi_ec_resume_noirq(struct device *dev) acpi_ec_leave_noirq(ec); return 0; } + +static int acpi_ec_resume(struct device *dev) +{ + struct acpi_ec *ec = + acpi_driver_data(to_acpi_device(dev)); + + acpi_ec_enable_event(ec); + return 0; +} #endif static const struct dev_pm_ops acpi_ec_pm = { SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(acpi_ec_suspend_noirq, acpi_ec_resume_noirq) + SET_SYSTEM_SLEEP_PM_OPS(NULL, acpi_ec_resume) }; static int param_set_event_clearing(const char *val, struct kernel_param *kp) -- cgit v1.2.3