From: "Lee, Chun-Yi" joeyli.kernel@gmail.com
There have some situation we unregister whole acpi/video driver by downstream driver just want to remove backlight control interface of acpi/video. It caues we lost other functions of acpi/video, e.g. transfer acpi event to input event.
So, this patch add a new function, find_video_unregister_backlight, it provide the interface let downstream driver can tell acpi/video to unregister backlight interface of all acpi video devices. Then we can keep functions of acpi/video but only remove backlight support.
Reference: bko#35622 https://bugzilla.kernel.org/show_bug.cgi?id=35622
v2: Also unregister cooling devices.
Tested-by: Andrzej Krentosz endrjux@gmail.com Cc: Zhang Rui rui.zhang@intel.com Cc: Len Brown lenb@kernel.org Cc: Rafael J. Wysocki rjw@sisk.pl Cc: Carlos Corbacho carlos@strangeworlds.co.uk Cc: Matthew Garrett mjg@redhat.com Cc: Dmitry Torokhov dtor@mail.ru Cc: Corentin Chary corentincj@iksaif.net Cc: Aaron Lu aaron.lu@intel.com Cc: Thomas Renninger trenn@suse.de Signed-off-by: Lee, Chun-Yi jlee@suse.com --- drivers/acpi/video.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++++---- include/acpi/video.h | 2 ++ 2 files changed, 89 insertions(+), 6 deletions(-)
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c index 5b32e15..da08ff7 100644 --- a/drivers/acpi/video.c +++ b/drivers/acpi/video.c @@ -43,6 +43,7 @@ #include <acpi/acpi_drivers.h> #include <linux/suspend.h> #include <acpi/video.h> +#include <linux/mutex.h>
#define PREFIX "ACPI: "
@@ -86,6 +87,9 @@ module_param(allow_duplicates, bool, 0644); static bool use_bios_initial_backlight = 1; module_param(use_bios_initial_backlight, bool, 0644);
+static bool backlight_disable; +module_param(backlight_disable, bool, 0644); + 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); @@ -214,6 +218,8 @@ static const char device_decode[][30] = { "UNKNOWN", };
+static DEFINE_MUTEX(backlight_mutex); + static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data); static void acpi_video_device_rebind(struct acpi_video_bus *video); static void acpi_video_device_bind(struct acpi_video_bus *video, @@ -882,7 +888,7 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device) device->cap._DDC = 1; }
- if (acpi_video_backlight_support()) { + if (acpi_video_backlight_support() || backlight_disable) { struct backlight_properties props; struct pci_dev *pdev; acpi_handle acpi_parent; @@ -1083,15 +1089,22 @@ acpi_video_bus_get_one_device(struct acpi_device *device, struct acpi_video_device *data; struct acpi_video_device_attrib* attribute;
+ mutex_lock(&backlight_mutex); + status = acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id); /* Some device omits _ADR, we skip them instead of fail */ - if (ACPI_FAILURE(status)) - return 0; + if (ACPI_FAILURE(status)) { + status = 0; + goto out; + }
data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL); - if (!data) - return -ENOMEM; + if (!data) { + status = -ENOMEM; + goto out; + } +
strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME); strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS); @@ -1156,6 +1169,8 @@ acpi_video_bus_get_one_device(struct acpi_device *device, list_add_tail(&data->entry, &video->video_device_list); mutex_unlock(&video->device_list_lock);
+out: + mutex_unlock(&backlight_mutex); return status; }
@@ -1336,7 +1351,7 @@ acpi_video_switch_brightness(struct acpi_video_device *device, int event) int result = -EINVAL;
/* no warning message if acpi_backlight=vendor is used */ - if (!acpi_video_backlight_support()) + if (!acpi_video_backlight_support() || backlight_disable) return 0;
if (!device->brightness) @@ -1869,6 +1884,72 @@ static int __init intel_opregion_present(void) return opregion; }
+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; + struct acpi_video_device *dev, *next; + acpi_status status = AE_OK; + + mutex_lock(&backlight_mutex); + + if (acpi_bus_get_device(handle, &acpi_dev)) + goto out; + + if (!acpi_match_device_ids(acpi_dev, video_device_ids)) { + video = acpi_driver_data(acpi_dev); + + if (!video) + goto out; + + 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); + } + if (dev->cooling_dev) { + sysfs_remove_link(&dev->dev->dev.kobj, + "thermal_cooling"); + sysfs_remove_link(&dev->cooling_dev->device.kobj, + "device"); + thermal_cooling_device_unregister(dev->cooling_dev); + dev->cooling_dev = NULL; + } + } + mutex_unlock(&video->device_list_lock); + acpi_video_bus_start_devices(video); + } +out: + mutex_unlock(&backlight_mutex); + return status; +} + +void acpi_video_backlight_unregister(void) +{ + if (!register_count) { + /* + * If the acpi video bus is already unloaded, don't + * unregister backlight of devices and return directly. + */ + return; + } + + backlight_disable = 1; + + 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) {