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Message-Id: <201012172234.02026.rjw@sisk.pl>
Date: Fri, 17 Dec 2010 22:34:01 +0100
From: "Rafael J. Wysocki" <rjw@...k.pl>
To: Len Brown <lenb@...nel.org>
Cc: LKML <linux-kernel@...r.kernel.org>,
ACPI Devel Maling List <linux-acpi@...r.kernel.org>,
Matthew Garrett <mjg59@...f.ucam.org>
Subject: [PATCH, regression fix] ACPI: Execute _PRW for devices reported as inactive or not present
From: Rafael J. Wysocki <rjw@...k.pl>
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@...k.pl>
Reported-by: Matthew Garrett <mjg@...hat.com>
---
Hi Len,
This patch fixes a post-2.6.36 regression introduced in the course of the GPE
rework, please apply.
Thanks,
Rafael
---
drivers/acpi/scan.c | 97 ++++++++++++++++++++++++++++++++--------------------
1 file changed, 60 insertions(+), 37 deletions(-)
Index: linux-2.6/drivers/acpi/scan.c
===================================================================
--- linux-2.6.orig/drivers/acpi/scan.c
+++ linux-2.6/drivers/acpi/scan.c
@@ -705,54 +705,85 @@ static int acpi_bus_get_perf_flags(struc
}
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)
@@ -787,26 +818,15 @@ static void acpi_bus_set_run_wake_flags(
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);
@@ -1368,6 +1388,7 @@ static acpi_status acpi_bus_check_add(ac
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;
@@ -1377,8 +1398,10 @@ static acpi_status acpi_bus_check_add(ac
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
--
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