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Commit 716e084e authored by Luming Yu's avatar Luming Yu Committed by Len Brown
Browse files

[ACPI] Fix "ec_burst=1" mode latency issue 

http://bugzilla.kernel.org/show_bug.cgi?id=3851



Signed-off-by: default avatarLuming Yu <luming.yu@intel.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent cbfc1bae

drivers/acpi/ec.c

+59 −110
Original line number Diff line number Diff line
@@ -234,18 +234,29 @@ static int acpi_ec_burst_wait(union acpi_ec *ec, unsigned int event) 
	ec->burst.expect_event = event;

	smp_mb();



	result = wait_event_interruptible_timeout(ec->burst.wait,

	switch (event) {

	case ACPI_EC_EVENT_OBF:

		if (acpi_ec_read_status(ec) & event) {

			ec->burst.expect_event = 0;

			return_VALUE(0);

		}

		break;



	case ACPI_EC_EVENT_IBE:

		if (~acpi_ec_read_status(ec) & event) {

			ec->burst.expect_event = 0;

			return_VALUE(0);

		}

		break;

	}



	result = wait_event_timeout(ec->burst.wait,

					!ec->burst.expect_event,

					msecs_to_jiffies(ACPI_EC_DELAY));

	

	ec->burst.expect_event = 0;

	smp_mb();



	if (result < 0){

		ACPI_DEBUG_PRINT((ACPI_DB_ERROR," result  = %d ", result));

		return_VALUE(result);

	}



	/*

	 * Verify that the event in question has actually happened by

	 * querying EC status. Do the check even if operation timed-out
@@ -280,14 +291,14 @@ acpi_ec_enter_burst_mode ( 
	status = acpi_ec_read_status(ec);

	if (status != -EINVAL &&

		!(status & ACPI_EC_FLAG_BURST)){

		status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);

		if(status)

			goto end;

		acpi_hw_low_level_write(8, ACPI_EC_BURST_ENABLE, &ec->common.command_addr);

		status = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);

		if (status){

			acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);

		if (status)

			return_VALUE(-EINVAL);

		}

		acpi_hw_low_level_read(8, &tmp, &ec->common.data_addr);

		acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);

		if(tmp != 0x90 ) {/* Burst ACK byte*/

			return_VALUE(-EINVAL);

		}
@@ -295,31 +306,19 @@ acpi_ec_enter_burst_mode ( 


	atomic_set(&ec->burst.leaving_burst , 0);

	return_VALUE(0);

end:

	printk("Error in acpi_ec_wait\n");

	return_VALUE(-1);

}



static int

acpi_ec_leave_burst_mode (

	union acpi_ec		*ec)

{

	int			status =0;



	ACPI_FUNCTION_TRACE("acpi_ec_leave_burst_mode");



	atomic_set(&ec->burst.leaving_burst, 1);

	status = acpi_ec_read_status(ec);

	if (status != -EINVAL &&

		(status & ACPI_EC_FLAG_BURST)){

		acpi_hw_low_level_write(8, ACPI_EC_BURST_DISABLE, &ec->common.command_addr);

		status = acpi_ec_wait(ec, ACPI_EC_FLAG_IBF);

		if (status){

			acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);

			ACPI_DEBUG_PRINT((ACPI_DB_ERROR,"------->wait fail\n"));

			return_VALUE(-EINVAL);

		}

		acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);

		status = acpi_ec_read_status(ec);

	}



	return_VALUE(0);

}
@@ -461,7 +460,6 @@ acpi_ec_burst_read ( 
	if (!ec || !data)

		return_VALUE(-EINVAL);



retry:

	*data = 0;



	if (ec->common.global_lock) {
@@ -473,26 +471,25 @@ acpi_ec_burst_read ( 
	WARN_ON(in_interrupt());

	down(&ec->burst.sem);



	if(acpi_ec_enter_burst_mode(ec))

	acpi_ec_enter_burst_mode(ec);

	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);

	if (status) {

		printk("read EC, IB not empty\n");

		goto end;



	}

	acpi_hw_low_level_write(8, ACPI_EC_COMMAND_READ, &ec->common.command_addr);

	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);

	acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);

	if (status) {

		goto end;

		printk("read EC, IB not empty\n");

	}



	acpi_hw_low_level_write(8, address, &ec->common.data_addr);

	status= acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);

	if (status){

		acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);

		printk("read EC, OB not full\n");

		goto end;

	}



	acpi_hw_low_level_read(8, data, &ec->common.data_addr);

	acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);



	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Read [%02x] from address [%02x]\n",

		*data, address));
@@ -503,15 +500,6 @@ acpi_ec_burst_read ( 
	if (ec->common.global_lock)

		acpi_release_global_lock(glk);



	if(atomic_read(&ec->burst.leaving_burst) == 2){

		ACPI_DEBUG_PRINT((ACPI_DB_INFO,"aborted, retry ...\n"));

		while(atomic_read(&ec->burst.pending_gpe)){

			msleep(1);	

		}

		acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);

		goto retry;

	}



	return_VALUE(status);

}
@@ -524,13 +512,12 @@ acpi_ec_burst_write ( 
{

	int			status = 0;

	u32			glk;

	u32			tmp;



	ACPI_FUNCTION_TRACE("acpi_ec_write");



	if (!ec)

		return_VALUE(-EINVAL);

retry:



	if (ec->common.global_lock) {

		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);

		if (ACPI_FAILURE(status))
@@ -540,61 +527,35 @@ acpi_ec_burst_write ( 
	WARN_ON(in_interrupt());

	down(&ec->burst.sem);



	if(acpi_ec_enter_burst_mode(ec))

		goto end;

	acpi_ec_enter_burst_mode(ec);



	status = acpi_ec_read_status(ec);

	if (status != -EINVAL &&

		!(status & ACPI_EC_FLAG_BURST)){

		acpi_hw_low_level_write(8, ACPI_EC_BURST_ENABLE, &ec->common.command_addr);

		status = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);

		if (status)

			goto end;

		acpi_hw_low_level_read(8, &tmp, &ec->common.data_addr);

		if(tmp != 0x90 ) /* Burst ACK byte*/

			goto end;

	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);

	if ( status) {

		printk("write EC, IB not empty\n");

	}

	/*Now we are in burst mode*/



	acpi_hw_low_level_write(8, ACPI_EC_COMMAND_WRITE, &ec->common.command_addr);

	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);

	acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);

	if (status) {

		goto end;

		printk ("write EC, IB not empty\n");

	}



	acpi_hw_low_level_write(8, address, &ec->common.data_addr);

	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);

	if (status){

		acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);

		goto end;

		printk("write EC, IB not empty\n");

	}



	acpi_hw_low_level_write(8, data, &ec->common.data_addr);

	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);

	acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);

	if (status)

		goto end;



	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Wrote [%02x] to address [%02x]\n",

		data, address));



end:

	acpi_ec_leave_burst_mode(ec);

	up(&ec->burst.sem);



	if (ec->common.global_lock)

		acpi_release_global_lock(glk);



	if(atomic_read(&ec->burst.leaving_burst) == 2){

		ACPI_DEBUG_PRINT((ACPI_DB_INFO,"aborted, retry ...\n"));

		while(atomic_read(&ec->burst.pending_gpe)){

			msleep(1);	

		}

		acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);

		goto retry;

	}



	return_VALUE(status);

}
@@ -719,8 +680,12 @@ acpi_ec_burst_query ( 
	}



	down(&ec->burst.sem);

	if(acpi_ec_enter_burst_mode(ec))



	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);

	if (status) {

		printk("query EC, IB not empty\n");

		goto end;

	}

	/*

	 * Query the EC to find out which _Qxx method we need to evaluate.

	 * Note that successful completion of the query causes the ACPI_EC_SCI
@@ -729,27 +694,20 @@ acpi_ec_burst_query ( 
	acpi_hw_low_level_write(8, ACPI_EC_COMMAND_QUERY, &ec->common.command_addr);

	status = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);

	if (status){

		acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);

		printk("query EC, OB not full\n");

		goto end;

	}



	acpi_hw_low_level_read(8, data, &ec->common.data_addr);

	acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);

	if (!*data)

		status = -ENODATA;



end:

	acpi_ec_leave_burst_mode(ec);

	up(&ec->burst.sem);



	if (ec->common.global_lock)

		acpi_release_global_lock(glk);



	if(atomic_read(&ec->burst.leaving_burst) == 2){

		ACPI_DEBUG_PRINT((ACPI_DB_INFO,"aborted, retry ...\n"));

		acpi_enable_gpe(NULL, ec->common.gpe_bit, ACPI_NOT_ISR);

		status = -ENODATA;

	}

	return_VALUE(status);

}
@@ -885,31 +843,21 @@ acpi_ec_gpe_burst_handler ( 
	if (!ec)

		return ACPI_INTERRUPT_NOT_HANDLED;



	acpi_disable_gpe(NULL, ec->common.gpe_bit, ACPI_ISR);



	acpi_clear_gpe(NULL, ec->common.gpe_bit, ACPI_ISR);

	value = acpi_ec_read_status(ec);



	if((value & ACPI_EC_FLAG_IBF) &&

		!(value & ACPI_EC_FLAG_BURST) &&

			(atomic_read(&ec->burst.leaving_burst) == 0)) { 

	/*

	 * the embedded controller disables 

	 * burst mode for any reason other 

	 * than the burst disable command

	 * to process critical event.

	 */

		atomic_set(&ec->burst.leaving_burst , 2); /* block current pending transaction

					and retry */

		wake_up(&ec->burst.wait);

	}else {

		if ((ec->burst.expect_event == ACPI_EC_EVENT_OBF &&

				(value & ACPI_EC_FLAG_OBF)) ||

	    			(ec->burst.expect_event == ACPI_EC_EVENT_IBE &&

				!(value & ACPI_EC_FLAG_IBF))) {

	switch ( ec->burst.expect_event) {

	case ACPI_EC_EVENT_OBF:

		if (!(value & ACPI_EC_FLAG_OBF))

			break;

	case ACPI_EC_EVENT_IBE:

		if ((value & ACPI_EC_FLAG_IBF))

			break;

		ec->burst.expect_event = 0;

		wake_up(&ec->burst.wait);

		return ACPI_INTERRUPT_HANDLED;

		}

	default:

		break;

	}



	if (value & ACPI_EC_FLAG_SCI){
@@ -1242,6 +1190,7 @@ acpi_ec_burst_add ( 
	if (result)

		goto end;



	printk("burst-mode-ec-10-Aug\n");

	printk(KERN_INFO PREFIX "%s [%s] (gpe %d)\n",

		acpi_device_name(device), acpi_device_bid(device),

		(u32) ec->common.gpe_bit);