Commit eb9299be authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

ACPI: EC: Use a spin lock without disabing interrupts 



Since all of the ACPI EC driver code runs in thread context after recent
changes, it does not need to disable interrupts on the local CPU when
acquiring a spin lock.

Make it use the spin lock without disabling interrupts.

Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 655a6e7c

drivers/acpi/ec.c

+46 −66
Original line number Diff line number Diff line
@@ -525,12 +525,10 @@ static void acpi_ec_clear(struct acpi_ec *ec) 


static void acpi_ec_enable_event(struct acpi_ec *ec)

{

	unsigned long flags;



	spin_lock_irqsave(&ec->lock, flags);

	spin_lock(&ec->lock);

	if (acpi_ec_started(ec))

		__acpi_ec_enable_event(ec);

	spin_unlock_irqrestore(&ec->lock, flags);

	spin_unlock(&ec->lock);



	/* Drain additional events if hardware requires that */

	if (EC_FLAGS_CLEAR_ON_RESUME)
@@ -546,11 +544,9 @@ static void __acpi_ec_flush_work(void) 


static void acpi_ec_disable_event(struct acpi_ec *ec)

{

	unsigned long flags;



	spin_lock_irqsave(&ec->lock, flags);

	spin_lock(&ec->lock);

	__acpi_ec_disable_event(ec);

	spin_unlock_irqrestore(&ec->lock, flags);

	spin_unlock(&ec->lock);



	/*

	 * When ec_freeze_events is true, we need to flush events in
@@ -571,10 +567,9 @@ void acpi_ec_flush_work(void) 


static bool acpi_ec_guard_event(struct acpi_ec *ec)

{

	unsigned long flags;

	bool guarded;



	spin_lock_irqsave(&ec->lock, flags);

	spin_lock(&ec->lock);

	/*

	 * If firmware SCI_EVT clearing timing is "event", we actually

	 * don't know when the SCI_EVT will be cleared by firmware after
@@ -590,31 +585,29 @@ static bool acpi_ec_guard_event(struct acpi_ec *ec) 
	guarded = ec_event_clearing == ACPI_EC_EVT_TIMING_EVENT &&

		ec->event_state != EC_EVENT_READY &&

		(!ec->curr || ec->curr->command != ACPI_EC_COMMAND_QUERY);

	spin_unlock_irqrestore(&ec->lock, flags);

	spin_unlock(&ec->lock);

	return guarded;

}



static int ec_transaction_polled(struct acpi_ec *ec)

{

	unsigned long flags;

	int ret = 0;



	spin_lock_irqsave(&ec->lock, flags);

	spin_lock(&ec->lock);

	if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_POLL))

		ret = 1;

	spin_unlock_irqrestore(&ec->lock, flags);

	spin_unlock(&ec->lock);

	return ret;

}



static int ec_transaction_completed(struct acpi_ec *ec)

{

	unsigned long flags;

	int ret = 0;



	spin_lock_irqsave(&ec->lock, flags);

	spin_lock(&ec->lock);

	if (ec->curr && (ec->curr->flags & ACPI_EC_COMMAND_COMPLETE))

		ret = 1;

	spin_unlock_irqrestore(&ec->lock, flags);

	spin_unlock(&ec->lock);

	return ret;

}
@@ -756,7 +749,6 @@ static int ec_guard(struct acpi_ec *ec) 


static int ec_poll(struct acpi_ec *ec)

{

	unsigned long flags;

	int repeat = 5; /* number of command restarts */



	while (repeat--) {
@@ -765,14 +757,14 @@ static int ec_poll(struct acpi_ec *ec) 
		do {

			if (!ec_guard(ec))

				return 0;

			spin_lock_irqsave(&ec->lock, flags);

			spin_lock(&ec->lock);

			advance_transaction(ec, false);

			spin_unlock_irqrestore(&ec->lock, flags);

			spin_unlock(&ec->lock);

		} while (time_before(jiffies, delay));

		pr_debug("controller reset, restart transaction\n");

		spin_lock_irqsave(&ec->lock, flags);

		spin_lock(&ec->lock);

		start_transaction(ec);

		spin_unlock_irqrestore(&ec->lock, flags);

		spin_unlock(&ec->lock);

	}

	return -ETIME;

}
@@ -780,11 +772,10 @@ static int ec_poll(struct acpi_ec *ec) 
static int acpi_ec_transaction_unlocked(struct acpi_ec *ec,

					struct transaction *t)

{

	unsigned long tmp;

	int ret = 0;



	/* start transaction */

	spin_lock_irqsave(&ec->lock, tmp);

	spin_lock(&ec->lock);

	/* Enable GPE for command processing (IBF=0/OBF=1) */

	if (!acpi_ec_submit_flushable_request(ec)) {

		ret = -EINVAL;
@@ -795,11 +786,11 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, 
	ec->curr = t;

	ec_dbg_req("Command(%s) started", acpi_ec_cmd_string(t->command));

	start_transaction(ec);

	spin_unlock_irqrestore(&ec->lock, tmp);

	spin_unlock(&ec->lock);



	ret = ec_poll(ec);



	spin_lock_irqsave(&ec->lock, tmp);

	spin_lock(&ec->lock);

	if (t->irq_count == ec_storm_threshold)

		acpi_ec_unmask_events(ec);

	ec_dbg_req("Command(%s) stopped", acpi_ec_cmd_string(t->command));
@@ -808,7 +799,7 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, 
	acpi_ec_complete_request(ec);

	ec_dbg_ref(ec, "Decrease command");

unlock:

	spin_unlock_irqrestore(&ec->lock, tmp);

	spin_unlock(&ec->lock);

	return ret;

}
@@ -936,9 +927,7 @@ EXPORT_SYMBOL(ec_get_handle); 


static void acpi_ec_start(struct acpi_ec *ec, bool resuming)

{

	unsigned long flags;



	spin_lock_irqsave(&ec->lock, flags);

	spin_lock(&ec->lock);

	if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) {

		ec_dbg_drv("Starting EC");

		/* Enable GPE for event processing (SCI_EVT=1) */
@@ -948,31 +937,28 @@ static void acpi_ec_start(struct acpi_ec *ec, bool resuming) 
		}

		ec_log_drv("EC started");

	}

	spin_unlock_irqrestore(&ec->lock, flags);

	spin_unlock(&ec->lock);

}



static bool acpi_ec_stopped(struct acpi_ec *ec)

{

	unsigned long flags;

	bool flushed;



	spin_lock_irqsave(&ec->lock, flags);

	spin_lock(&ec->lock);

	flushed = acpi_ec_flushed(ec);

	spin_unlock_irqrestore(&ec->lock, flags);

	spin_unlock(&ec->lock);

	return flushed;

}



static void acpi_ec_stop(struct acpi_ec *ec, bool suspending)

{

	unsigned long flags;



	spin_lock_irqsave(&ec->lock, flags);

	spin_lock(&ec->lock);

	if (acpi_ec_started(ec)) {

		ec_dbg_drv("Stopping EC");

		set_bit(EC_FLAGS_STOPPED, &ec->flags);

		spin_unlock_irqrestore(&ec->lock, flags);

		spin_unlock(&ec->lock);

		wait_event(ec->wait, acpi_ec_stopped(ec));

		spin_lock_irqsave(&ec->lock, flags);

		spin_lock(&ec->lock);

		/* Disable GPE for event processing (SCI_EVT=1) */

		if (!suspending) {

			acpi_ec_complete_request(ec);
@@ -983,29 +969,25 @@ static void acpi_ec_stop(struct acpi_ec *ec, bool suspending) 
		clear_bit(EC_FLAGS_STOPPED, &ec->flags);

		ec_log_drv("EC stopped");

	}

	spin_unlock_irqrestore(&ec->lock, flags);

	spin_unlock(&ec->lock);

}



static void acpi_ec_enter_noirq(struct acpi_ec *ec)

{

	unsigned long flags;



	spin_lock_irqsave(&ec->lock, flags);

	spin_lock(&ec->lock);

	ec->busy_polling = true;

	ec->polling_guard = 0;

	ec_log_drv("interrupt blocked");

	spin_unlock_irqrestore(&ec->lock, flags);

	spin_unlock(&ec->lock);

}



static void acpi_ec_leave_noirq(struct acpi_ec *ec)

{

	unsigned long flags;



	spin_lock_irqsave(&ec->lock, flags);

	spin_lock(&ec->lock);

	ec->busy_polling = ec_busy_polling;

	ec->polling_guard = ec_polling_guard;

	ec_log_drv("interrupt unblocked");

	spin_unlock_irqrestore(&ec->lock, flags);

	spin_unlock(&ec->lock);

}



void acpi_ec_block_transactions(void)
@@ -1137,9 +1119,9 @@ static void acpi_ec_event_processor(struct work_struct *work) 


	ec_dbg_evt("Query(0x%02x) stopped", handler->query_bit);



	spin_lock_irq(&ec->lock);

	spin_lock(&ec->lock);

	ec->queries_in_progress--;

	spin_unlock_irq(&ec->lock);

	spin_unlock(&ec->lock);



	acpi_ec_put_query_handler(handler);

	kfree(q);
@@ -1202,12 +1184,12 @@ static int acpi_ec_submit_query(struct acpi_ec *ec) 
	 */

	ec_dbg_evt("Query(0x%02x) scheduled", value);



	spin_lock_irq(&ec->lock);

	spin_lock(&ec->lock);



	ec->queries_in_progress++;

	queue_work(ec_query_wq, &q->work);



	spin_unlock_irq(&ec->lock);

	spin_unlock(&ec->lock);



	return 0;
@@ -1223,14 +1205,14 @@ static void acpi_ec_event_handler(struct work_struct *work) 


	ec_dbg_evt("Event started");



	spin_lock_irq(&ec->lock);

	spin_lock(&ec->lock);



	while (ec->events_to_process) {

		spin_unlock_irq(&ec->lock);

		spin_unlock(&ec->lock);



		acpi_ec_submit_query(ec);



		spin_lock_irq(&ec->lock);

		spin_lock(&ec->lock);



		ec->events_to_process--;

	}
@@ -1247,11 +1229,11 @@ static void acpi_ec_event_handler(struct work_struct *work) 


		ec_dbg_evt("Event stopped");



		spin_unlock_irq(&ec->lock);

		spin_unlock(&ec->lock);



		guard_timeout = !!ec_guard(ec);



		spin_lock_irq(&ec->lock);

		spin_lock(&ec->lock);



		/* Take care of SCI_EVT unless someone else is doing that. */

		if (guard_timeout && !ec->curr)
@@ -1264,7 +1246,7 @@ static void acpi_ec_event_handler(struct work_struct *work) 


	ec->events_in_progress--;



	spin_unlock_irq(&ec->lock);

	spin_unlock(&ec->lock);

}



static void clear_gpe_and_advance_transaction(struct acpi_ec *ec, bool interrupt)
@@ -1289,13 +1271,11 @@ static void clear_gpe_and_advance_transaction(struct acpi_ec *ec, bool interrupt 


static void acpi_ec_handle_interrupt(struct acpi_ec *ec)

{

	unsigned long flags;



	spin_lock_irqsave(&ec->lock, flags);

	spin_lock(&ec->lock);



	clear_gpe_and_advance_transaction(ec, true);



	spin_unlock_irqrestore(&ec->lock, flags);

	spin_unlock(&ec->lock);

}



static u32 acpi_ec_gpe_handler(acpi_handle gpe_device,
@@ -2105,7 +2085,7 @@ bool acpi_ec_dispatch_gpe(void) 
	 * Dispatch the EC GPE in-band, but do not report wakeup in any case

	 * to allow the caller to process events properly after that.

	 */

	spin_lock_irq(&first_ec->lock);

	spin_lock(&first_ec->lock);



	if (acpi_ec_gpe_status_set(first_ec)) {

		pm_pr_dbg("ACPI EC GPE status set\n");
@@ -2114,7 +2094,7 @@ bool acpi_ec_dispatch_gpe(void) 
		work_in_progress = acpi_ec_work_in_progress(first_ec);

	}



	spin_unlock_irq(&first_ec->lock);

	spin_unlock(&first_ec->lock);



	if (!work_in_progress)

		return false;
@@ -2127,11 +2107,11 @@ bool acpi_ec_dispatch_gpe(void) 


		pm_pr_dbg("ACPI EC work flushed\n");



		spin_lock_irq(&first_ec->lock);

		spin_lock(&first_ec->lock);



		work_in_progress = acpi_ec_work_in_progress(first_ec);



		spin_unlock_irq(&first_ec->lock);

		spin_unlock(&first_ec->lock);

	} while (work_in_progress && !pm_wakeup_pending());



	return false;