aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--drivers/acpi/video.c279
-rw-r--r--drivers/acpi/video_detect.c3
-rw-r--r--drivers/gpu/drm/i915/i915_dma.c5
-rw-r--r--drivers/gpu/drm/i915/i915_drv.c2
-rw-r--r--drivers/gpu/drm/i915/i915_drv.h4
-rw-r--r--drivers/gpu/drm/i915/i915_opregion.c65
-rw-r--r--include/acpi/video.h11
7 files changed, 306 insertions, 63 deletions
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index 5259d502add..100c8eeaa5d 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -37,6 +37,8 @@
#include <linux/thermal.h>
#include <linux/video_output.h>
#include <linux/sort.h>
+#include <linux/pci.h>
+#include <linux/pci_ids.h>
#include <asm/uaccess.h>
#include <acpi/acpi_bus.h>
@@ -162,16 +164,26 @@ struct acpi_video_device_cap {
u8 _BCL:1; /*Query list of brightness control levels supported */
u8 _BCM:1; /*Set the brightness level */
u8 _BQC:1; /* Get current brightness level */
+ u8 _BCQ:1; /* Some buggy BIOS uses _BCQ instead of _BQC */
u8 _DDC:1; /*Return the EDID for this device */
u8 _DCS:1; /*Return status of output device */
u8 _DGS:1; /*Query graphics state */
u8 _DSS:1; /*Device state set */
};
+struct acpi_video_brightness_flags {
+ u8 _BCL_no_ac_battery_levels:1; /* no AC/Battery levels in _BCL */
+ u8 _BCL_reversed:1; /* _BCL package is in a reversed order*/
+ u8 _BCL_use_index:1; /* levels in _BCL are index values */
+ u8 _BCM_use_index:1; /* input of _BCM is an index value */
+ u8 _BQC_use_index:1; /* _BQC returns an index value */
+};
+
struct acpi_video_device_brightness {
int curr;
int count;
int *levels;
+ struct acpi_video_brightness_flags flags;
};
struct acpi_video_device {
@@ -294,7 +306,7 @@ static int acpi_video_device_lcd_get_level_current(
unsigned long long *level);
static int acpi_video_get_next_level(struct acpi_video_device *device,
u32 level_current, u32 event);
-static void acpi_video_switch_brightness(struct acpi_video_device *device,
+static int acpi_video_switch_brightness(struct acpi_video_device *device,
int event);
static int acpi_video_device_get_state(struct acpi_video_device *device,
unsigned long long *state);
@@ -308,7 +320,9 @@ static int acpi_video_get_brightness(struct backlight_device *bd)
int i;
struct acpi_video_device *vd =
(struct acpi_video_device *)bl_get_data(bd);
- acpi_video_device_lcd_get_level_current(vd, &cur_level);
+
+ if (acpi_video_device_lcd_get_level_current(vd, &cur_level))
+ return -EINVAL;
for (i = 2; i < vd->brightness->count; i++) {
if (vd->brightness->levels[i] == cur_level)
/* The first two entries are special - see page 575
@@ -320,12 +334,12 @@ static int acpi_video_get_brightness(struct backlight_device *bd)
static int acpi_video_set_brightness(struct backlight_device *bd)
{
- int request_level = bd->props.brightness+2;
+ int request_level = bd->props.brightness + 2;
struct acpi_video_device *vd =
(struct acpi_video_device *)bl_get_data(bd);
- acpi_video_device_lcd_set_level(vd,
- vd->brightness->levels[request_level]);
- return 0;
+
+ return acpi_video_device_lcd_set_level(vd,
+ vd->brightness->levels[request_level]);
}
static struct backlight_ops acpi_backlight_ops = {
@@ -376,7 +390,8 @@ static int video_get_cur_state(struct thermal_cooling_device *cdev, unsigned
unsigned long long level;
int offset;
- acpi_video_device_lcd_get_level_current(video, &level);
+ if (acpi_video_device_lcd_get_level_current(video, &level))
+ return -EINVAL;
for (offset = 2; offset < video->brightness->count; offset++)
if (level == video->brightness->levels[offset]) {
*state = video->brightness->count - offset - 1;
@@ -483,34 +498,68 @@ acpi_video_device_lcd_query_levels(struct acpi_video_device *device,
static int
acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level)
{
- int status = AE_OK;
+ int status;
union acpi_object arg0 = { ACPI_TYPE_INTEGER };
struct acpi_object_list args = { 1, &arg0 };
int state;
-
arg0.integer.value = level;
- if (device->cap._BCM)
- status = acpi_evaluate_object(device->dev->handle, "_BCM",
- &args, NULL);
+ status = acpi_evaluate_object(device->dev->handle, "_BCM",
+ &args, NULL);
+ if (ACPI_FAILURE(status)) {
+ ACPI_ERROR((AE_INFO, "Evaluating _BCM failed"));
+ return -EIO;
+ }
+
device->brightness->curr = level;
for (state = 2; state < device->brightness->count; state++)
- if (level == device->brightness->levels[state])
- device->backlight->props.brightness = state - 2;
+ if (level == device->brightness->levels[state]) {
+ if (device->backlight)
+ device->backlight->props.brightness = state - 2;
+ return 0;
+ }
- return status;
+ ACPI_ERROR((AE_INFO, "Current brightness invalid"));
+ return -EINVAL;
}
static int
acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
unsigned long long *level)
{
- if (device->cap._BQC)
- return acpi_evaluate_integer(device->dev->handle, "_BQC", NULL,
- level);
+ acpi_status status = AE_OK;
+
+ if (device->cap._BQC || device->cap._BCQ) {
+ char *buf = device->cap._BQC ? "_BQC" : "_BCQ";
+
+ status = acpi_evaluate_integer(device->dev->handle, buf,
+ NULL, level);
+ if (ACPI_SUCCESS(status)) {
+ if (device->brightness->flags._BQC_use_index) {
+ if (device->brightness->flags._BCL_reversed)
+ *level = device->brightness->count
+ - 3 - (*level);
+ *level = device->brightness->levels[*level + 2];
+
+ }
+ device->brightness->curr = *level;
+ return 0;
+ } else {
+ /* Fixme:
+ * should we return an error or ignore this failure?
+ * dev->brightness->curr is a cached value which stores
+ * the correct current backlight level in most cases.
+ * ACPI video backlight still works w/ buggy _BQC.
+ * http://bugzilla.kernel.org/show_bug.cgi?id=12233
+ */
+ ACPI_WARNING((AE_INFO, "Evaluating %s failed", buf));
+ device->cap._BQC = device->cap._BCQ = 0;
+ }
+ }
+
*level = device->brightness->curr;
- return AE_OK;
+ return 0;
}
static int
@@ -659,9 +708,11 @@ static int
acpi_video_init_brightness(struct acpi_video_device *device)
{
union acpi_object *obj = NULL;
- int i, max_level = 0, count = 0;
+ int i, max_level = 0, count = 0, level_ac_battery = 0;
+ unsigned long long level, level_old;
union acpi_object *o;
struct acpi_video_device_brightness *br = NULL;
+ int result = -EINVAL;
if (!ACPI_SUCCESS(acpi_video_device_lcd_query_levels(device, &obj))) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Could not query available "
@@ -675,13 +726,16 @@ acpi_video_init_brightness(struct acpi_video_device *device)
br = kzalloc(sizeof(*br), GFP_KERNEL);
if (!br) {
printk(KERN_ERR "can't allocate memory\n");
+ result = -ENOMEM;
goto out;
}
- br->levels = kmalloc(obj->package.count * sizeof *(br->levels),
+ br->levels = kmalloc((obj->package.count + 2) * sizeof *(br->levels),
GFP_KERNEL);
- if (!br->levels)
+ if (!br->levels) {
+ result = -ENOMEM;
goto out_free;
+ }
for (i = 0; i < obj->package.count; i++) {
o = (union acpi_object *)&obj->package.elements[i];
@@ -696,18 +750,86 @@ acpi_video_init_brightness(struct acpi_video_device *device)
count++;
}
- /* don't sort the first two brightness levels */
- sort(&br->levels[2], count - 2, sizeof(br->levels[2]),
- acpi_video_cmp_level, NULL);
-
- if (count < 2)
- goto out_free_levels;
+ /*
+ * some buggy BIOS don't export the levels
+ * when machine is on AC/Battery in _BCL package.
+ * In this case, the first two elements in _BCL packages
+ * are also supported brightness levels that OS should take care of.
+ */
+ for (i = 2; i < count; i++)
+ if (br->levels[i] == br->levels[0] ||
+ br->levels[i] == br->levels[1])
+ level_ac_battery++;
+
+ if (level_ac_battery < 2) {
+ level_ac_battery = 2 - level_ac_battery;
+ br->flags._BCL_no_ac_battery_levels = 1;
+ for (i = (count - 1 + level_ac_battery); i >= 2; i--)
+ br->levels[i] = br->levels[i - level_ac_battery];
+ count += level_ac_battery;
+ } else if (level_ac_battery > 2)
+ ACPI_ERROR((AE_INFO, "Too many duplicates in _BCL package\n"));
+
+ /* Check if the _BCL package is in a reversed order */
+ if (max_level == br->levels[2]) {
+ br->flags._BCL_reversed = 1;
+ sort(&br->levels[2], count - 2, sizeof(br->levels[2]),
+ acpi_video_cmp_level, NULL);
+ } else if (max_level != br->levels[count - 1])
+ ACPI_ERROR((AE_INFO,
+ "Found unordered _BCL package\n"));
br->count = count;
device->brightness = br;
- ACPI_DEBUG_PRINT((ACPI_DB_INFO, "found %d brightness levels\n", count));
+
+ /* Check the input/output of _BQC/_BCL/_BCM */
+ if ((max_level < 100) && (max_level <= (count - 2)))
+ br->flags._BCL_use_index = 1;
+
+ /*
+ * _BCM is always consistent with _BCL,
+ * at least for all the laptops we have ever seen.
+ */
+ br->flags._BCM_use_index = br->flags._BCL_use_index;
+
+ /* _BQC uses INDEX while _BCL uses VALUE in some laptops */
+ br->curr = max_level;
+ result = acpi_video_device_lcd_get_level_current(device, &level_old);
+ if (result)
+ goto out_free_levels;
+
+ result = acpi_video_device_lcd_set_level(device, br->curr);
+ if (result)
+ goto out_free_levels;
+
+ result = acpi_video_device_lcd_get_level_current(device, &level);
+ if (result)
+ goto out_free_levels;
+
+ if ((level != level_old) && !br->flags._BCM_use_index) {
+ /* Note:
+ * This piece of code does not work correctly if the current
+ * brightness levels is 0.
+ * But I guess boxes that boot with such a dark screen are rare
+ * and no more code is needed to cover this specifial case.
+ */
+
+ if (level_ac_battery != 2) {
+ /*
+ * For now, we don't support the _BCL like this:
+ * 16, 15, 0, 1, 2, 3, ..., 14, 15, 16
+ * because we may mess up the index returned by _BQC.
+ * Plus: we have not got a box like this.
+ */
+ ACPI_ERROR((AE_INFO, "_BCL not supported\n"));
+ }
+ br->flags._BQC_use_index = 1;
+ }
+
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+ "found %d brightness levels\n", count - 2));
kfree(obj);
- return max_level;
+ return result;
out_free_levels:
kfree(br->levels);
@@ -716,7 +838,7 @@ out_free:
out:
device->brightness = NULL;
kfree(obj);
- return 0;
+ return result;
}
/*
@@ -733,7 +855,6 @@ out:
static void acpi_video_device_find_cap(struct acpi_video_device *device)
{
acpi_handle h_dummy1;
- u32 max_level = 0;
memset(&device->cap, 0, sizeof(device->cap));
@@ -749,6 +870,12 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device)
}
if (ACPI_SUCCESS(acpi_get_handle(device->dev->handle,"_BQC",&h_dummy1)))
device->cap._BQC = 1;
+ else if (ACPI_SUCCESS(acpi_get_handle(device->dev->handle, "_BCQ",
+ &h_dummy1))) {
+ printk(KERN_WARNING FW_BUG "_BCQ is used instead of _BQC\n");
+ device->cap._BCQ = 1;
+ }
+
if (ACPI_SUCCESS(acpi_get_handle(device->dev->handle, "_DDC", &h_dummy1))) {
device->cap._DDC = 1;
}
@@ -762,13 +889,14 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device)
device->cap._DSS = 1;
}
- if (acpi_video_backlight_support())
- max_level = acpi_video_init_brightness(device);
-
- if (device->cap._BCL && device->cap._BCM && max_level > 0) {
+ if (acpi_video_backlight_support()) {
int result;
static int count = 0;
char *name;
+
+ result = acpi_video_init_brightness(device);
+ if (result)
+ return;
name = kzalloc(MAX_NAME_LEN, GFP_KERNEL);
if (!name)
return;
@@ -777,18 +905,6 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device)
device->backlight = backlight_device_register(name,
NULL, device, &acpi_backlight_ops);
device->backlight->props.max_brightness = device->brightness->count-3;
- /*
- * If there exists the _BQC object, the _BQC object will be
- * called to get the current backlight brightness. Otherwise
- * the brightness will be set to the maximum.
- */
- if (device->cap._BQC)
- device->backlight->props.brightness =
- acpi_video_get_brightness(device->backlight);
- else
- device->backlight->props.brightness =
- device->backlight->props.max_brightness;
- backlight_update_status(device->backlight);
kfree(name);
device->cdev = thermal_cooling_device_register("LCD",
@@ -1065,13 +1181,12 @@ acpi_video_device_write_brightness(struct file *file,
/* validate through the list of available levels */
for (i = 2; i < dev->brightness->count; i++)
if (level == dev->brightness->levels[i]) {
- if (ACPI_SUCCESS
- (acpi_video_device_lcd_set_level(dev, level)))
- dev->brightness->curr = level;
+ if (!acpi_video_device_lcd_set_level(dev, level))
+ return count;
break;
}
- return count;
+ return -EINVAL;
}
static int acpi_video_device_EDID_seq_show(struct seq_file *seq, void *offset)
@@ -1753,15 +1868,29 @@ acpi_video_get_next_level(struct acpi_video_device *device,
}
}
-static void
+static int
acpi_video_switch_brightness(struct acpi_video_device *device, int event)
{
unsigned long long level_current, level_next;
+ int result = -EINVAL;
+
if (!device->brightness)
- return;
- acpi_video_device_lcd_get_level_current(device, &level_current);
+ goto out;
+
+ result = acpi_video_device_lcd_get_level_current(device,
+ &level_current);
+ if (result)
+ goto out;
+
level_next = acpi_video_get_next_level(device, level_current, event);
- acpi_video_device_lcd_set_level(device, level_next);
+
+ result = acpi_video_device_lcd_set_level(device, level_next);
+
+out:
+ if (result)
+ printk(KERN_ERR PREFIX "Failed to switch the brightness\n");
+
+ return result;
}
static int
@@ -2128,7 +2257,27 @@ static int acpi_video_bus_remove(struct acpi_device *device, int type)
return 0;
}
-static int __init acpi_video_init(void)
+static int __init intel_opregion_present(void)
+{
+#if defined(CONFIG_DRM_I915) || defined(CONFIG_DRM_I915_MODULE)
+ struct pci_dev *dev = NULL;
+ u32 address;
+
+ for_each_pci_dev(dev) {
+ if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
+ continue;
+ if (dev->vendor != PCI_VENDOR_ID_INTEL)
+ continue;
+ pci_read_config_dword(dev, 0xfc, &address);
+ if (!address)
+ continue;
+ return 1;
+ }
+#endif
+ return 0;
+}
+
+int acpi_video_register(void)
{
int result = 0;
@@ -2145,6 +2294,22 @@ static int __init acpi_video_init(void)
return 0;
}
+EXPORT_SYMBOL(acpi_video_register);
+
+/*
+ * This is kind of nasty. Hardware using Intel chipsets may require
+ * the video opregion code to be run first in order to initialise
+ * state before any ACPI video calls are made. To handle this we defer
+ * registration of the video class until the opregion code has run.
+ */
+
+static int __init acpi_video_init(void)
+{
+ if (intel_opregion_present())
+ return 0;
+
+ return acpi_video_register();
+}
static void __exit acpi_video_exit(void)
{
diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
index 50e3d2dbf3a..09737275e25 100644
--- a/drivers/acpi/video_detect.c
+++ b/drivers/acpi/video_detect.c
@@ -55,6 +55,9 @@ acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found generic backlight "
"support\n"));
*cap |= ACPI_VIDEO_BACKLIGHT;
+ if (ACPI_FAILURE(acpi_get_handle(handle, "_BQC", &h_dummy)))
+ printk(KERN_WARNING FW_BUG PREFIX "ACPI brightness "
+ "control misses _BQC function\n");
/* We have backlight support, no need to scan further */
return AE_CTRL_TERMINATE;
}
diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 6d21b9e48b8..638686904e0 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1144,8 +1144,6 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
if (!IS_I945G(dev) && !IS_I945GM(dev))
pci_enable_msi(dev->pdev);
- intel_opregion_init(dev);
-
spin_lock_init(&dev_priv->user_irq_lock);
dev_priv->user_irq_refcount = 0;
@@ -1164,6 +1162,9 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
}
}
+ /* Must be done after probing outputs */
+ intel_opregion_init(dev, 0);
+
return 0;
out_iomapfree:
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index b293ef0bae7..209592fdb7e 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -99,7 +99,7 @@ static int i915_resume(struct drm_device *dev)
i915_restore_state(dev);
- intel_opregion_init(dev);
+ intel_opregion_init(dev, 1);
/* KMS EnterVT equivalent */
if (drm_core_check_feature(dev, DRIVER_MODESET)) {
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index d6cc9861e0a..b9a92c250b9 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -659,12 +659,12 @@ extern int i915_restore_state(struct drm_device *dev);
#ifdef CONFIG_ACPI
/* i915_opregion.c */
-extern int intel_opregion_init(struct drm_device *dev);
+extern int intel_opregion_init(struct drm_device *dev, int resume);
extern void intel_opregion_free(struct drm_device *dev);
extern void opregion_asle_intr(struct drm_device *dev);
extern void opregion_enable_asle(struct drm_device *dev);
#else
-static inline int intel_opregion_init(struct drm_device *dev) { return 0; }
+static inline int intel_opregion_init(struct drm_device *dev, int resume) { return 0; }
static inline void intel_opregion_free(struct drm_device *dev) { return; }
static inline void opregion_asle_intr(struct drm_device *dev) { return; }
static inline void opregion_enable_asle(struct drm_device *dev) { return; }
diff --git a/drivers/gpu/drm/i915/i915_opregion.c b/drivers/gpu/drm/i915/i915_opregion.c
index ff012835a38..69427722d20 100644
--- a/drivers/gpu/drm/i915/i915_opregion.c
+++ b/drivers/gpu/drm/i915/i915_opregion.c
@@ -26,6 +26,7 @@
*/
#include <linux/acpi.h>
+#include <acpi/video.h>
#include "drmP.h"
#include "i915_drm.h"
@@ -136,6 +137,12 @@ struct opregion_asle {
#define ASLE_CBLV_VALID (1<<31)
+#define ACPI_OTHER_OUTPUT (0<<8)
+#define ACPI_VGA_OUTPUT (1<<8)
+#define ACPI_TV_OUTPUT (2<<8)
+#define ACPI_DIGITAL_OUTPUT (3<<8)
+#define ACPI_LVDS_OUTPUT (4<<8)
+
static u32 asle_set_backlight(struct drm_device *dev, u32 bclp)
{
struct drm_i915_private *dev_priv = dev->dev_private;
@@ -282,7 +289,58 @@ static struct notifier_block intel_opregion_notifier = {
.notifier_call = intel_opregion_video_event,
};
-int intel_opregion_init(struct drm_device *dev)
+/*
+ * Initialise the DIDL field in opregion. This passes a list of devices to
+ * the firmware. Values are defined by section B.4.2 of the ACPI specification
+ * (version 3)
+ */
+
+static void intel_didl_outputs(struct drm_device *dev)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ struct intel_opregion *opregion = &dev_priv->opregion;
+ struct drm_connector *connector;
+ int i = 0;
+
+ list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
+ int output_type = ACPI_OTHER_OUTPUT;
+ if (i >= 8) {
+ dev_printk (KERN_ERR, &dev->pdev->dev,
+ "More than 8 outputs detected\n");
+ return;
+ }
+ switch (connector->connector_type) {
+ case DRM_MODE_CONNECTOR_VGA:
+ case DRM_MODE_CONNECTOR_DVIA:
+ output_type = ACPI_VGA_OUTPUT;
+ break;
+ case DRM_MODE_CONNECTOR_Composite:
+ case DRM_MODE_CONNECTOR_SVIDEO:
+ case DRM_MODE_CONNECTOR_Component:
+ case DRM_MODE_CONNECTOR_9PinDIN:
+ output_type = ACPI_TV_OUTPUT;
+ break;
+ case DRM_MODE_CONNECTOR_DVII:
+ case DRM_MODE_CONNECTOR_DVID:
+ case DRM_MODE_CONNECTOR_DisplayPort:
+ case DRM_MODE_CONNECTOR_HDMIA:
+ case DRM_MODE_CONNECTOR_HDMIB:
+ output_type = ACPI_DIGITAL_OUTPUT;
+ break;
+ case DRM_MODE_CONNECTOR_LVDS:
+ output_type = ACPI_LVDS_OUTPUT;
+ break;
+ }
+ opregion->acpi->didl[i] |= (1<<31) | output_type | i;
+ i++;
+ }
+
+ /* If fewer than 8 outputs, the list must be null terminated */
+ if (i < 8)
+ opregion->acpi->didl[i] = 0;
+}
+
+int intel_opregion_init(struct drm_device *dev, int resume)
{
struct drm_i915_private *dev_priv = dev->dev_private;
struct intel_opregion *opregion = &dev_priv->opregion;
@@ -312,6 +370,11 @@ int intel_opregion_init(struct drm_device *dev)
if (mboxes & MBOX_ACPI) {
DRM_DEBUG("Public ACPI methods supported\n");
opregion->acpi = base + OPREGION_ACPI_OFFSET;
+ if (drm_core_check_feature(dev, DRIVER_MODESET)) {
+ intel_didl_outputs(dev);
+ if (!resume)
+ acpi_video_register();
+ }
} else {
DRM_DEBUG("Public ACPI methods not supported\n");
err = -ENOTSUPP;
diff --git a/include/acpi/video.h b/include/acpi/video.h
new file mode 100644
index 00000000000..f0275bb79ce
--- /dev/null
+++ b/include/acpi/video.h
@@ -0,0 +1,11 @@
+#ifndef __ACPI_VIDEO_H
+#define __ACPI_VIDEO_H
+
+#if (defined CONFIG_ACPI_VIDEO || defined CONFIG_ACPI_VIDEO_MODULE)
+extern int acpi_video_register(void);
+#else
+static inline int acpi_video_register(void) { return 0; }
+#endif
+
+#endif
+