Skip to content

Commit

Permalink
ACPI: Execute _PRW for devices reported as inactive or not present
Browse files Browse the repository at this point in the history 
If a device is reported as inactive or not present by its _STA
control method, acpi_bus_check_add() skips it without evaluating its
_PRW method.  This leads to a problem when the device's _PRW method
points to a GPE, because in that case the GPE may be enabled by
ACPICA during the subsequent acpi_update_gpes() call which, in
turn, may cause a GPE storm to appear.

To avoid this issue, make acpi_bus_check_add() evaluate _PRW for
inactive or not present devices and register the wakeup GPE
information returned by them, so that acpi_update_gpes() does not
enable their GPEs unnecessarily.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>
  • Loading branch information
Rafael J. Wysocki authored and Len Brown committed Dec 17, 2010
1 parent cf7d7e5 commit b581a7f
Showing 1 changed file with 60 additions and 37 deletions.
97 changes: 60 additions & 37 deletions drivers/acpi/scan.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -705,54 +705,85 @@ static int acpi_bus_get_perf_flags(struct acpi_device *device)
}

static acpi_status
acpi_bus_extract_wakeup_device_power_package(struct acpi_device *device,
union acpi_object *package)
acpi_bus_extract_wakeup_device_power_package(acpi_handle handle,
struct acpi_device_wakeup *wakeup)
{
int i = 0;
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
union acpi_object *package = NULL;
union acpi_object *element = NULL;
acpi_status status;
int i = 0;

if (!device || !package || (package->package.count < 2))
if (!wakeup)
return AE_BAD_PARAMETER;

/* _PRW */
status = acpi_evaluate_object(handle, "_PRW", NULL, &buffer);
if (ACPI_FAILURE(status)) {
ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
return status;
}

package = (union acpi_object *)buffer.pointer;

if (!package || (package->package.count < 2)) {
status = AE_BAD_DATA;
goto out;
}

element = &(package->package.elements[0]);
if (!element)
return AE_BAD_PARAMETER;
if (!element) {
status = AE_BAD_DATA;
goto out;
}
if (element->type == ACPI_TYPE_PACKAGE) {
if ((element->package.count < 2) ||
(element->package.elements[0].type !=
ACPI_TYPE_LOCAL_REFERENCE)
|| (element->package.elements[1].type != ACPI_TYPE_INTEGER))
return AE_BAD_DATA;
device->wakeup.gpe_device =
|| (element->package.elements[1].type != ACPI_TYPE_INTEGER)) {
status = AE_BAD_DATA;
goto out;
}
wakeup->gpe_device =
element->package.elements[0].reference.handle;
device->wakeup.gpe_number =
wakeup->gpe_number =
(u32) element->package.elements[1].integer.value;
} else if (element->type == ACPI_TYPE_INTEGER) {
device->wakeup.gpe_number = element->integer.value;
} else
return AE_BAD_DATA;
wakeup->gpe_device = NULL;
wakeup->gpe_number = element->integer.value;
} else {
status = AE_BAD_DATA;
goto out;
}

element = &(package->package.elements[1]);
if (element->type != ACPI_TYPE_INTEGER) {
return AE_BAD_DATA;
status = AE_BAD_DATA;
goto out;
}
device->wakeup.sleep_state = element->integer.value;
wakeup->sleep_state = element->integer.value;

if ((package->package.count - 2) > ACPI_MAX_HANDLES) {
return AE_NO_MEMORY;
status = AE_NO_MEMORY;
goto out;
}
device->wakeup.resources.count = package->package.count - 2;
for (i = 0; i < device->wakeup.resources.count; i++) {
wakeup->resources.count = package->package.count - 2;
for (i = 0; i < wakeup->resources.count; i++) {
element = &(package->package.elements[i + 2]);
if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
return AE_BAD_DATA;
if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
status = AE_BAD_DATA;
goto out;
}

device->wakeup.resources.handles[i] = element->reference.handle;
wakeup->resources.handles[i] = element->reference.handle;
}

acpi_gpe_can_wake(device->wakeup.gpe_device, device->wakeup.gpe_number);
acpi_gpe_can_wake(wakeup->gpe_device, wakeup->gpe_number);

return AE_OK;
out:
kfree(buffer.pointer);

return status;
}

static void acpi_bus_set_run_wake_flags(struct acpi_device *device)
Expand Down Expand Up @@ -787,26 +818,15 @@ static void acpi_bus_set_run_wake_flags(struct acpi_device *device)
static int acpi_bus_get_wakeup_device_flags(struct acpi_device *device)
{
acpi_status status = 0;
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
union acpi_object *package = NULL;
int psw_error;

/* _PRW */
status = acpi_evaluate_object(device->handle, "_PRW", NULL, &buffer);
if (ACPI_FAILURE(status)) {
ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PRW"));
goto end;
}

package = (union acpi_object *)buffer.pointer;
status = acpi_bus_extract_wakeup_device_power_package(device, package);
status = acpi_bus_extract_wakeup_device_power_package(device->handle,
&device->wakeup);
if (ACPI_FAILURE(status)) {
ACPI_EXCEPTION((AE_INFO, status, "Extracting _PRW package"));
goto end;
}

kfree(buffer.pointer);

device->wakeup.flags.valid = 1;
device->wakeup.prepare_count = 0;
acpi_bus_set_run_wake_flags(device);
Expand Down Expand Up @@ -1351,6 +1371,7 @@ static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl,
struct acpi_bus_ops *ops = context;
int type;
unsigned long long sta;
struct acpi_device_wakeup wakeup;
struct acpi_device *device;
acpi_status status;
int result;
Expand All @@ -1360,8 +1381,10 @@ static acpi_status acpi_bus_check_add(acpi_handle handle, u32 lvl,
return AE_OK;

if (!(sta & ACPI_STA_DEVICE_PRESENT) &&
!(sta & ACPI_STA_DEVICE_FUNCTIONING))
!(sta & ACPI_STA_DEVICE_FUNCTIONING)) {
acpi_bus_extract_wakeup_device_power_package(handle, &wakeup);
return AE_CTRL_DEPTH;
}

/*
* We may already have an acpi_device from a previous enumeration. If
Expand Down

0 comments on commit b581a7f

Please sign in to comment.