From c8890f903a6fdf5711726e8e8d65cb13423f8833 Mon Sep 17 00:00:00 2001 From: Zhang Rui Date: Wed, 18 Mar 2009 16:27:08 +0800 Subject: [PATCH] ACPI video: check the return value of acpi_video_device_lcd_get_level_current Signed-off-by: Zhang Rui Acked-by: Matthew Garrett Acked-by: Thomas Renninger Signed-off-by: Len Brown --- drivers/acpi/video.c | 55 ++++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 45 insertions(+), 10 deletions(-) diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c index bb5ed059114..f0e6eb53416 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 -- 2.11.4.GIT