On Mon, Apr 22, 2013 at 08:39:15PM +0800, Chun-Yi Lee wrote: > From: "Lee, Chun-Yi" <jlee@xxxxxxxx> > +static acpi_status > +find_video_unregister_backlight(acpi_handle handle, u32 lvl, void *context, > + void **rv) > +{ > + struct acpi_device *acpi_dev; > + struct acpi_video_bus *video = NULL; Gratuitous initialization of local variables prevents compiler from warning when you using variable uninitialized. > + struct acpi_video_device *dev, *next; > + > + if (acpi_bus_get_device(handle, &acpi_dev)) > + return AE_OK; > + > + if (!acpi_match_device_ids(acpi_dev, video_device_ids)) { > + video = acpi_driver_data(acpi_dev); > + acpi_video_bus_stop_devices(video); > + mutex_lock(&video->device_list_lock); > + list_for_each_entry_safe(dev, next, &video->video_device_list, > + entry) { > + if (dev->backlight) { > + backlight_device_unregister(dev->backlight); > + dev->backlight = NULL; > + kfree(dev->brightness->levels); > + kfree(dev->brightness); > + } > + } > + mutex_unlock(&video->device_list_lock); > + acpi_video_bus_start_devices(video); > + } > + return AE_OK; > +} > + > +void acpi_video_backlight_unregister(void) > +{ > + if (!register_count) { Locking? It looks like the rest of the driver ignores locking too... > + /* > + * If the acpi video bus is already unloaded, don't > + * unregister backlight of devices and return directly. > + */ > + return; > + } > + acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, > + ACPI_UINT32_MAX, find_video_unregister_backlight, > + NULL, NULL, NULL); > + return; > +} > +EXPORT_SYMBOL(acpi_video_backlight_unregister); > + > int acpi_video_register(void) > { > int result = 0; > diff --git a/include/acpi/video.h b/include/acpi/video.h > index 61109f2..1e810a1 100644 > --- a/include/acpi/video.h > +++ b/include/acpi/video.h > @@ -19,11 +19,13 @@ struct acpi_device; > #if (defined CONFIG_ACPI_VIDEO || defined CONFIG_ACPI_VIDEO_MODULE) > extern int acpi_video_register(void); > extern void acpi_video_unregister(void); > +extern void acpi_video_backlight_unregister(void); > extern int acpi_video_get_edid(struct acpi_device *device, int type, > int device_id, void **edid); > #else > static inline int acpi_video_register(void) { return 0; } > static inline void acpi_video_unregister(void) { return; } > +static inline void acpi_video_backlight_unregister(void) { return; } > static inline int acpi_video_get_edid(struct acpi_device *device, int type, > int device_id, void **edid) > { > -- > 1.8.1.4 > > Thanks. -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html