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[ACPI] Fix "ec_burst=1" mode latency issue
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http://bugzilla.kernel.org/show_bug.cgi?id=3851

Signed-off-by: Luming Yu <luming.yu@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
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Luming Yu authored and Len Brown committed Aug 11, 2005
1 parent cbfc1ba commit 716e084
Showing 1 changed file with 59 additions and 110 deletions.
169 changes: 59 additions & 110 deletions drivers/acpi/ec.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down Expand Up @@ -280,46 +291,34 @@ 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);
}
}

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);
}

atomic_set(&ec->burst.leaving_burst, 1);
return_VALUE(0);
}

Expand Down Expand Up @@ -461,7 +460,6 @@ acpi_ec_burst_read (
if (!ec || !data)
return_VALUE(-EINVAL);

retry:
*data = 0;

if (ec->common.global_lock) {
Expand All @@ -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));

Expand All @@ -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);
}

Expand All @@ -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))
Expand All @@ -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;
if (status) {
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);
}

Expand Down Expand Up @@ -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
Expand All @@ -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);
}

Expand Down Expand Up @@ -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 */
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);
}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))) {
ec->burst.expect_event = 0;
wake_up(&ec->burst.wait);
return ACPI_INTERRUPT_HANDLED;
}
return ACPI_INTERRUPT_HANDLED;
default:
break;
}

if (value & ACPI_EC_FLAG_SCI){
Expand Down Expand Up @@ -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);
Expand Down

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