[PATCH 88/98] ACPI video: check the return value of acpi_video_device_lcd_get_level_current

Len Brown
2009-03-28T04:33:48Z

From: Zhang Rui <rui.zhang@intel.com>

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Acked-by: Matthew Garrett <mjg59@srcf.ucam.org>
Acked-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>
---
drivers/acpi/video.c | 55 ++++++++++++++++++++++++++++++++++++++++---------
1 files changed, 45 insertions(+), 10 deletions(-)

diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index bb5ed05..f0e6eb5 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -294,7 +294,7 @@ 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 +308,9 @@ 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
@@ -373,7 +375,8 @@ static int video_get_cur_state(struct thermal_cooling_device *cdev, char *buf)
unsigned long long level;
int state;

- acpi_video_device_lcd_get_level_current(video, &level);
+ if (acpi_video_device_lcd_get_level_current(video, &level))
+ return -EINVAL;
for (state = 2; state < video->brightness->count; state++)
if (level == video->brightness->levels[state])
return sprintf(buf, "%d\n",
@@ -502,11 +505,29 @@ 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) {
+ status = acpi_evaluate_integer(device->dev->handle, "_BQC",
+ NULL, level);
+ if (ACPI_SUCCESS(status)) {
+ 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 _BQC failed"));
+ device->cap._BQC = 0;
+ }
+ }
+
*level = device->brightness->curr;
- return AE_OK;
+ return 0;
}

static int
@@ -1749,15 +1770,29 @@ 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);
+
+out:
+ if (result)
+ printk(KERN_ERR PREFIX "Failed to switch the brightness\n");
+
+ return result;
}

static int
--
1.6.0.6