ACPI / PM: Move ACPI video resume to a PM notifier
There is a problem with the ACPI video resume routine that it's
executed before the GPU that may be accessed by it. To fix this
issue, move the ACPI video resume to a power management notifier,
so that's executed after resuming all devices, including the GPU.
Fixes https://bugzilla.kernel.org/show_bug.cgi?id=15096, which is
a listed regression from 2.6.31.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-by: Rafał Miłecki <zajec5@gmail.com>
Acked-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index 6a01437..416eb03 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -44,6 +44,7 @@
#include <linux/dmi.h>
#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>
+#include <linux/suspend.h>
#define PREFIX "ACPI: "
@@ -89,7 +90,6 @@
static int register_count = 0;
static int acpi_video_bus_add(struct acpi_device *device);
static int acpi_video_bus_remove(struct acpi_device *device, int type);
-static int acpi_video_resume(struct acpi_device *device);
static void acpi_video_bus_notify(struct acpi_device *device, u32 event);
static const struct acpi_device_id video_device_ids[] = {
@@ -105,7 +105,6 @@
.ops = {
.add = acpi_video_bus_add,
.remove = acpi_video_bus_remove,
- .resume = acpi_video_resume,
.notify = acpi_video_bus_notify,
},
};
@@ -160,6 +159,7 @@
struct proc_dir_entry *dir;
struct input_dev *input;
char phys[32]; /* for input device */
+ struct notifier_block pm_nb;
};
struct acpi_video_device_flags {
@@ -1021,6 +1021,13 @@
if (IS_ERR(device->backlight))
return;
+ /*
+ * Save current brightness level in case we have to restore it
+ * before acpi_video_device_lcd_set_level() is called next time.
+ */
+ device->backlight->props.brightness =
+ acpi_video_get_brightness(device->backlight);
+
result = sysfs_create_link(&device->backlight->dev.kobj,
&device->dev->dev.kobj, "device");
if (result)
@@ -2236,24 +2243,31 @@
return;
}
-static int instance;
-static int acpi_video_resume(struct acpi_device *device)
+static int acpi_video_resume(struct notifier_block *nb,
+ unsigned long val, void *ign)
{
struct acpi_video_bus *video;
struct acpi_video_device *video_device;
int i;
- if (!device || !acpi_driver_data(device))
- return -EINVAL;
+ switch (val) {
+ case PM_HIBERNATION_PREPARE:
+ case PM_SUSPEND_PREPARE:
+ case PM_RESTORE_PREPARE:
+ return NOTIFY_DONE;
+ }
- video = acpi_driver_data(device);
+ video = container_of(nb, struct acpi_video_bus, pm_nb);
+
+ dev_info(&video->device->dev, "Restoring backlight state\n");
for (i = 0; i < video->attached_count; i++) {
video_device = video->attached_array[i].bind_info;
if (video_device && video_device->backlight)
acpi_video_set_brightness(video_device->backlight);
}
- return AE_OK;
+
+ return NOTIFY_OK;
}
static acpi_status
@@ -2277,6 +2291,8 @@
return AE_OK;
}
+static int instance;
+
static int acpi_video_bus_add(struct acpi_device *device)
{
struct acpi_video_bus *video;
@@ -2370,6 +2386,10 @@
video->flags.rom ? "yes" : "no",
video->flags.post ? "yes" : "no");
+ video->pm_nb.notifier_call = acpi_video_resume;
+ video->pm_nb.priority = 0;
+ register_pm_notifier(&video->pm_nb);
+
return 0;
err_free_input_dev:
@@ -2396,6 +2416,8 @@
video = acpi_driver_data(device);
+ unregister_pm_notifier(&video->pm_nb);
+
acpi_video_bus_stop_devices(video);
acpi_video_bus_put_devices(video);
acpi_video_bus_remove_fs(device);
