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ACPI / ACPICA: Fix low-level GPE manipulation code
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ACPICA uses acpi_ev_enable_gpe() for enabling GPEs at the low level,
which is incorrect, because this function only enables the GPE if the
corresponding bit in its enable register's enable_for_run mask is set.
This causes acpi_set_gpe() to work incorrectly if used for enabling
GPEs that were not previously enabled with acpi_enable_gpe().  As a
result, among other things, wakeup-only GPEs are never enabled by
acpi_enable_wakeup_device(), so the devices that use them are unable
to wake up the system.

To fix this issue remove acpi_ev_enable_gpe() and its counterpart
acpi_ev_disable_gpe() and replace acpi_hw_low_disable_gpe() with
acpi_hw_low_set_gpe() that will be used instead to manipulate GPE
enable bits at the low level.  Make the users of acpi_ev_enable_gpe()
and acpi_ev_disable_gpe() call acpi_hw_low_set_gpe() instead and
make sure that GPE enable masks are only updated by acpi_enable_gpe()
and acpi_disable_gpe() when GPE reference counters change from 0
to 1 and from 1 to 0, respectively.

Signed-off-by: Rafael J. Wysocki <[email protected]>
Signed-off-by: Len Brown <[email protected]>
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rjwysocki authored and lenb committed Jun 12, 2010
1 parent e4e9a73 commit fd24744
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Showing 6 changed files with 79 additions and 123 deletions.
4 changes: 0 additions & 4 deletions drivers/acpi/acpica/acevents.h
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Original file line number Diff line number Diff line change
Expand Up @@ -78,10 +78,6 @@ acpi_ev_queue_notify_request(struct acpi_namespace_node *node,
acpi_status
acpi_ev_update_gpe_enable_masks(struct acpi_gpe_event_info *gpe_event_info);

acpi_status acpi_ev_enable_gpe(struct acpi_gpe_event_info *gpe_event_info);

acpi_status acpi_ev_disable_gpe(struct acpi_gpe_event_info *gpe_event_info);

struct acpi_gpe_event_info *acpi_ev_get_gpe_event_info(acpi_handle gpe_device,
u32 gpe_number);

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3 changes: 2 additions & 1 deletion drivers/acpi/acpica/achware.h
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Original file line number Diff line number Diff line change
Expand Up @@ -93,7 +93,8 @@ acpi_status acpi_hw_write_port(acpi_io_address address, u32 value, u32 width);
u32 acpi_hw_gpe_register_bit(struct acpi_gpe_event_info *gpe_event_info,
struct acpi_gpe_register_info *gpe_register_info);

acpi_status acpi_hw_low_disable_gpe(struct acpi_gpe_event_info *gpe_event_info);
acpi_status
acpi_hw_low_set_gpe(struct acpi_gpe_event_info *gpe_event_info, u8 action);

acpi_status
acpi_hw_write_gpe_enable_reg(struct acpi_gpe_event_info *gpe_event_info);
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108 changes: 2 additions & 106 deletions drivers/acpi/acpica/evgpe.c
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Original file line number Diff line number Diff line change
Expand Up @@ -99,106 +99,6 @@ acpi_ev_update_gpe_enable_masks(struct acpi_gpe_event_info *gpe_event_info)
return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
*
* FUNCTION: acpi_ev_enable_gpe
*
* PARAMETERS: gpe_event_info - GPE to enable
*
* RETURN: Status
*
* DESCRIPTION: Hardware-enable a GPE. Always enables the GPE, regardless
* of type or number of references.
*
* Note: The GPE lock should be already acquired when this function is called.
*
******************************************************************************/

acpi_status acpi_ev_enable_gpe(struct acpi_gpe_event_info *gpe_event_info)
{
acpi_status status;


ACPI_FUNCTION_TRACE(ev_enable_gpe);


/*
* We will only allow a GPE to be enabled if it has either an
* associated method (_Lxx/_Exx) or a handler. Otherwise, the
* GPE will be immediately disabled by acpi_ev_gpe_dispatch the
* first time it fires.
*/
if (!(gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK)) {
return_ACPI_STATUS(AE_NO_HANDLER);
}

/* Ensure the HW enable masks are current */

status = acpi_ev_update_gpe_enable_masks(gpe_event_info);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}

/* Clear the GPE (of stale events) */

status = acpi_hw_clear_gpe(gpe_event_info);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}

/* Enable the requested GPE */

status = acpi_hw_write_gpe_enable_reg(gpe_event_info);
return_ACPI_STATUS(status);
}

/*******************************************************************************
*
* FUNCTION: acpi_ev_disable_gpe
*
* PARAMETERS: gpe_event_info - GPE to disable
*
* RETURN: Status
*
* DESCRIPTION: Hardware-disable a GPE. Always disables the requested GPE,
* regardless of the type or number of references.
*
* Note: The GPE lock should be already acquired when this function is called.
*
******************************************************************************/

acpi_status acpi_ev_disable_gpe(struct acpi_gpe_event_info *gpe_event_info)
{
acpi_status status;

ACPI_FUNCTION_TRACE(ev_disable_gpe);


/*
* Note: Always disable the GPE, even if we think that that it is already
* disabled. It is possible that the AML or some other code has enabled
* the GPE behind our back.
*/

/* Ensure the HW enable masks are current */

status = acpi_ev_update_gpe_enable_masks(gpe_event_info);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}

/*
* Always H/W disable this GPE, even if we don't know the GPE type.
* Simply clear the enable bit for this particular GPE, but do not
* write out the current GPE enable mask since this may inadvertently
* enable GPEs too early. An example is a rogue GPE that has arrived
* during ACPICA initialization - possibly because AML or other code
* has enabled the GPE.
*/
status = acpi_hw_low_disable_gpe(gpe_event_info);
return_ACPI_STATUS(status);
}


/*******************************************************************************
*
Expand Down Expand Up @@ -450,10 +350,6 @@ static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
return_VOID;
}

/* Update the GPE register masks for return to enabled state */

(void)acpi_ev_update_gpe_enable_masks(gpe_event_info);

/*
* Take a snapshot of the GPE info for this level - we copy the info to
* prevent a race condition with remove_handler/remove_block.
Expand Down Expand Up @@ -606,7 +502,7 @@ acpi_ev_gpe_dispatch(struct acpi_gpe_event_info *gpe_event_info, u32 gpe_number)
* Disable the GPE, so it doesn't keep firing before the method has a
* chance to run (it runs asynchronously with interrupts enabled).
*/
status = acpi_ev_disable_gpe(gpe_event_info);
status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
if (ACPI_FAILURE(status)) {
ACPI_EXCEPTION((AE_INFO, status,
"Unable to disable GPE[0x%2X]",
Expand Down Expand Up @@ -643,7 +539,7 @@ acpi_ev_gpe_dispatch(struct acpi_gpe_event_info *gpe_event_info, u32 gpe_number)
* Disable the GPE. The GPE will remain disabled a handler
* is installed or ACPICA is restarted.
*/
status = acpi_ev_disable_gpe(gpe_event_info);
status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
if (ACPI_FAILURE(status)) {
ACPI_EXCEPTION((AE_INFO, status,
"Unable to disable GPE[0x%2X]",
Expand Down
59 changes: 53 additions & 6 deletions drivers/acpi/acpica/evxfevnt.c
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Original file line number Diff line number Diff line change
Expand Up @@ -199,6 +199,44 @@ acpi_status acpi_enable_event(u32 event, u32 flags)

ACPI_EXPORT_SYMBOL(acpi_enable_event)

/*******************************************************************************
*
* FUNCTION: acpi_clear_and_enable_gpe
*
* PARAMETERS: gpe_event_info - GPE to enable
*
* RETURN: Status
*
* DESCRIPTION: Clear the given GPE from stale events and enable it.
*
******************************************************************************/
static acpi_status
acpi_clear_and_enable_gpe(struct acpi_gpe_event_info *gpe_event_info)
{
acpi_status status;

/*
* We will only allow a GPE to be enabled if it has either an
* associated method (_Lxx/_Exx) or a handler. Otherwise, the
* GPE will be immediately disabled by acpi_ev_gpe_dispatch the
* first time it fires.
*/
if (!(gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK)) {
return_ACPI_STATUS(AE_NO_HANDLER);
}

/* Clear the GPE (of stale events) */
status = acpi_hw_clear_gpe(gpe_event_info);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}

/* Enable the requested GPE */
status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_ENABLE);

return_ACPI_STATUS(status);
}

/*******************************************************************************
*
* FUNCTION: acpi_set_gpe
Expand Down Expand Up @@ -240,11 +278,11 @@ acpi_status acpi_set_gpe(acpi_handle gpe_device, u32 gpe_number, u8 action)

switch (action) {
case ACPI_GPE_ENABLE:
status = acpi_ev_enable_gpe(gpe_event_info);
status = acpi_clear_and_enable_gpe(gpe_event_info);
break;

case ACPI_GPE_DISABLE:
status = acpi_ev_disable_gpe(gpe_event_info);
status = acpi_hw_low_set_gpe(gpe_event_info, ACPI_GPE_DISABLE);
break;

default:
Expand Down Expand Up @@ -307,7 +345,11 @@ acpi_status acpi_enable_gpe(acpi_handle gpe_device, u32 gpe_number, u8 gpe_type)

gpe_event_info->runtime_count++;
if (gpe_event_info->runtime_count == 1) {
status = acpi_ev_enable_gpe(gpe_event_info);
status = acpi_ev_update_gpe_enable_masks(gpe_event_info);
if (ACPI_SUCCESS(status)) {
status = acpi_clear_and_enable_gpe(gpe_event_info);
}

if (ACPI_FAILURE(status)) {
gpe_event_info->runtime_count--;
goto unlock_and_exit;
Expand All @@ -334,7 +376,7 @@ acpi_status acpi_enable_gpe(acpi_handle gpe_device, u32 gpe_number, u8 gpe_type)
*/
gpe_event_info->wakeup_count++;
if (gpe_event_info->wakeup_count == 1) {
(void)acpi_ev_update_gpe_enable_masks(gpe_event_info);
status = acpi_ev_update_gpe_enable_masks(gpe_event_info);
}
}

Expand Down Expand Up @@ -394,7 +436,12 @@ acpi_status acpi_disable_gpe(acpi_handle gpe_device, u32 gpe_number, u8 gpe_type

gpe_event_info->runtime_count--;
if (!gpe_event_info->runtime_count) {
status = acpi_ev_disable_gpe(gpe_event_info);
status = acpi_ev_update_gpe_enable_masks(gpe_event_info);
if (ACPI_SUCCESS(status)) {
status = acpi_hw_low_set_gpe(gpe_event_info,
ACPI_GPE_DISABLE);
}

if (ACPI_FAILURE(status)) {
gpe_event_info->runtime_count++;
goto unlock_and_exit;
Expand All @@ -415,7 +462,7 @@ acpi_status acpi_disable_gpe(acpi_handle gpe_device, u32 gpe_number, u8 gpe_type

gpe_event_info->wakeup_count--;
if (!gpe_event_info->wakeup_count) {
(void)acpi_ev_update_gpe_enable_masks(gpe_event_info);
status = acpi_ev_update_gpe_enable_masks(gpe_event_info);
}
}

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26 changes: 21 additions & 5 deletions drivers/acpi/acpica/hwgpe.c
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Original file line number Diff line number Diff line change
Expand Up @@ -78,23 +78,27 @@ u32 acpi_hw_gpe_register_bit(struct acpi_gpe_event_info *gpe_event_info,

/******************************************************************************
*
* FUNCTION: acpi_hw_low_disable_gpe
* FUNCTION: acpi_hw_low_set_gpe
*
* PARAMETERS: gpe_event_info - Info block for the GPE to be disabled
* action - Enable or disable
*
* RETURN: Status
*
* DESCRIPTION: Disable a single GPE in the enable register.
* DESCRIPTION: Enable or disable a single GPE in its enable register.
*
******************************************************************************/

acpi_status acpi_hw_low_disable_gpe(struct acpi_gpe_event_info *gpe_event_info)
acpi_status
acpi_hw_low_set_gpe(struct acpi_gpe_event_info *gpe_event_info, u8 action)
{
struct acpi_gpe_register_info *gpe_register_info;
acpi_status status;
u32 enable_mask;
u32 register_bit;

ACPI_FUNCTION_ENTRY();

/* Get the info block for the entire GPE register */

gpe_register_info = gpe_event_info->register_info;
Expand All @@ -109,11 +113,23 @@ acpi_status acpi_hw_low_disable_gpe(struct acpi_gpe_event_info *gpe_event_info)
return (status);
}

/* Clear just the bit that corresponds to this GPE */
/* Set ot clear just the bit that corresponds to this GPE */

register_bit = acpi_hw_gpe_register_bit(gpe_event_info,
gpe_register_info);
ACPI_CLEAR_BIT(enable_mask, register_bit);
switch (action) {
case ACPI_GPE_ENABLE:
ACPI_SET_BIT(enable_mask, register_bit);
break;

case ACPI_GPE_DISABLE:
ACPI_CLEAR_BIT(enable_mask, register_bit);
break;

default:
ACPI_ERROR((AE_INFO, "Invalid action\n"));
return (AE_BAD_PARAMETER);
}

/* Write the updated enable mask */

Expand Down
2 changes: 1 addition & 1 deletion include/acpi/actypes.h
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Original file line number Diff line number Diff line change
Expand Up @@ -663,7 +663,7 @@ typedef u32 acpi_event_status;
#define ACPI_GPE_MAX 0xFF
#define ACPI_NUM_GPE 256

/* Actions for acpi_set_gpe */
/* Actions for acpi_set_gpe and acpi_hw_low_set_gpe */

#define ACPI_GPE_ENABLE 0
#define ACPI_GPE_DISABLE 1
Expand Down

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