ACPI / ACPICA: Fix low-level GPE manipulation code

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 <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 2 insertions, 106 deletions

diff --git a/drivers/acpi/acpica/evgpe.c b/drivers/acpi/acpica/evgpe.c
index 57eeb3bde41e..66cd03835d6e 100644
--- a/drivers/acpi/acpica/evgpe.c
+++ b/drivers/acpi/acpica/evgpe.c
@@ -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);
-}
-
 
 /*******************************************************************************
  *
@@ -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.
@@ -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]",
@@ -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]",