diff options
| -rw-r--r-- | drivers/acpi/acpi_video.c | 39 |
1 files changed, 26 insertions, 13 deletions
diff --git a/drivers/acpi/acpi_video.c b/drivers/acpi/acpi_video.c index 2ea1781290cc..ade02152bb06 100644 --- a/drivers/acpi/acpi_video.c +++ b/drivers/acpi/acpi_video.c @@ -2182,6 +2182,30 @@ static bool dmi_is_desktop(void) return false; } +/* + * We're seeing a lot of bogus backlight interfaces on newer machines + * without a LCD such as desktops, servers and HDMI sticks. Checking the + * lcd flag fixes this, enable this by default on any machines which are: + * 1. Win8 ready (where we also prefer the native backlight driver, so + * normally the acpi_video code should not register there anyways); *and* + * 2.1 Report a desktop/server DMI chassis-type, or + * 2.2 Are an ACPI-reduced-hardware platform (and thus won't use the EC for + backlight control) + */ +static bool should_check_lcd_flag(void) +{ + if (!acpi_osi_is_win8()) + return false; + + if (dmi_is_desktop()) + return true; + + if (acpi_reduced_hardware()) + return true; + + return false; +} + int acpi_video_register(void) { int ret = 0; @@ -2195,19 +2219,8 @@ int acpi_video_register(void) goto leave; } - /* - * We're seeing a lot of bogus backlight interfaces on newer machines - * without a LCD such as desktops, servers and HDMI sticks. Checking - * the lcd flag fixes this, so enable this on any machines which are - * win8 ready (where we also prefer the native backlight driver, so - * normally the acpi_video code should not register there anyways). - */ - if (only_lcd == -1) { - if (dmi_is_desktop() && acpi_osi_is_win8()) - only_lcd = true; - else - only_lcd = false; - } + if (only_lcd == -1) + only_lcd = should_check_lcd_flag(); dmi_check_system(video_dmi_table); |