From 28f4f8a9def2b1f3a6066bae791c77043ec49524 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 3 Aug 2010 23:55:14 +0200 Subject: ACPI / ACPICA: Fix reference counting problems with GPE handlers If a handler is installed for a GPE associated with an AML method and such that it cannot wake up the system from sleep states, the GPE remains enabled after the handler has been installed, although it should be disabled in that case to avoid spurious execution of the handler. Fix this issue by making acpi_install_gpe_handler() disable GPEs that were previously associated with AML methods and cannot wake up the system from sleep states. Analogously, make acpi_remove_gpe_handler() enable the GPEs that are associated with AML methods after their handlers have been removed and cannot wake up the system from sleep states. In addition to that, fix a code ordering issue in acpi_remove_gpe_handler() that renders the locking ineffective (ACPI_MTX_EVENTS is released temporarily in the middle of the routine to wait for the completion of events already in progress). For this purpose introduce acpi_raw_disable_gpe() and acpi_raw_enable_gpe() to be called with acpi_gbl_gpe_lock held and rework acpi_disable_gpe() and acpi_enable_gpe(), respectively, to use them. Also rework acpi_gpe_can_wake() to use acpi_raw_disable_gpe() instead of calling acpi_disable_gpe() after releasing the lock to avoid the possible theoretical race with acpi_install_gpe_handler(). Signed-off-by: Rafael J. Wysocki Cc: "Moore, Robert" Cc: Lin Ming Signed-off-by: Len Brown --- drivers/acpi/acpica/evgpe.c | 73 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) (limited to 'drivers/acpi/acpica/evgpe.c') diff --git a/drivers/acpi/acpica/evgpe.c b/drivers/acpi/acpica/evgpe.c index 7a6a3e6f..f226eac 100644 --- a/drivers/acpi/acpica/evgpe.c +++ b/drivers/acpi/acpica/evgpe.c @@ -137,6 +137,79 @@ acpi_ev_enable_gpe(struct acpi_gpe_event_info *gpe_event_info) /******************************************************************************* * + * FUNCTION: acpi_raw_enable_gpe + * + * PARAMETERS: gpe_event_info - GPE to enable + * + * RETURN: Status + * + * DESCRIPTION: Add a reference to a GPE. On the first reference, the GPE is + * hardware-enabled. + * + ******************************************************************************/ + +acpi_status acpi_raw_enable_gpe(struct acpi_gpe_event_info *gpe_event_info) +{ + acpi_status status = AE_OK; + + if (gpe_event_info->runtime_count == ACPI_UINT8_MAX) { + return_ACPI_STATUS(AE_LIMIT); + } + + gpe_event_info->runtime_count++; + if (gpe_event_info->runtime_count == 1) { + status = acpi_ev_update_gpe_enable_mask(gpe_event_info); + if (ACPI_SUCCESS(status)) { + status = acpi_ev_enable_gpe(gpe_event_info); + } + + if (ACPI_FAILURE(status)) { + gpe_event_info->runtime_count--; + } + } + + return_ACPI_STATUS(status); +} + +/******************************************************************************* + * + * FUNCTION: acpi_raw_disable_gpe + * + * PARAMETERS: gpe_event_info - GPE to disable + * + * RETURN: Status + * + * DESCRIPTION: Remove a reference to a GPE. When the last reference is + * removed, the GPE is hardware-disabled. + * + ******************************************************************************/ + +acpi_status acpi_raw_disable_gpe(struct acpi_gpe_event_info *gpe_event_info) +{ + acpi_status status = AE_OK; + + if (!gpe_event_info->runtime_count) { + return_ACPI_STATUS(AE_LIMIT); + } + + gpe_event_info->runtime_count--; + if (!gpe_event_info->runtime_count) { + status = acpi_ev_update_gpe_enable_mask(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++; + } + } + + return_ACPI_STATUS(status); +} + +/******************************************************************************* + * * FUNCTION: acpi_ev_low_get_gpe_info * * PARAMETERS: gpe_number - Raw GPE number -- cgit v1.1