diff options
Diffstat (limited to 'drivers/acpi/video_detect.c')
| -rw-r--r-- | drivers/acpi/video_detect.c | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c index 5d7f38016a24..5f105eaa7d30 100644 --- a/drivers/acpi/video_detect.c +++ b/drivers/acpi/video_detect.c @@ -17,8 +17,9 @@ * Otherwise vendor specific drivers like thinkpad_acpi, asus-laptop, * sony_acpi,... can take care about backlight brightness. * - * Backlight drivers can use acpi_video_get_backlight_type() to determine - * which driver should handle the backlight. + * Backlight drivers can use acpi_video_get_backlight_type() to determine which + * driver should handle the backlight. RAW/GPU-driver backlight drivers must + * use the acpi_video_backlight_use_native() helper for this. * * If CONFIG_ACPI_VIDEO is neither set as "compiled in" (y) nor as a module (m) * this file will not be compiled and acpi_video_get_backlight_type() will @@ -571,9 +572,10 @@ static int acpi_video_backlight_notify(struct notifier_block *nb, * Arguably the native on win8 check should be done first, but that would * be a behavior change, which may causes issues. */ -enum acpi_backlight_type acpi_video_get_backlight_type(void) +static enum acpi_backlight_type __acpi_video_get_backlight_type(bool native) { static DEFINE_MUTEX(init_mutex); + static bool native_available; static bool init_done; static long video_caps; @@ -593,6 +595,8 @@ enum acpi_backlight_type acpi_video_get_backlight_type(void) backlight_notifier_registered = true; init_done = true; } + if (native) + native_available = true; mutex_unlock(&init_mutex); if (acpi_backlight_cmdline != acpi_backlight_undef) @@ -604,13 +608,25 @@ enum acpi_backlight_type acpi_video_get_backlight_type(void) if (!(video_caps & ACPI_VIDEO_BACKLIGHT)) return acpi_backlight_vendor; - if (acpi_osi_is_win8() && backlight_device_get_by_type(BACKLIGHT_RAW)) + if (acpi_osi_is_win8() && + (native_available || backlight_device_get_by_type(BACKLIGHT_RAW))) return acpi_backlight_native; return acpi_backlight_video; } + +enum acpi_backlight_type acpi_video_get_backlight_type(void) +{ + return __acpi_video_get_backlight_type(false); +} EXPORT_SYMBOL(acpi_video_get_backlight_type); +bool acpi_video_backlight_use_native(void) +{ + return __acpi_video_get_backlight_type(true) == acpi_backlight_native; +} +EXPORT_SYMBOL(acpi_video_backlight_use_native); + /* * Set the preferred backlight interface type based on DMI info. * This function allows DMI blacklists to be implemented by external |