toshiba_acpi: Fix blank screen at boot if transflective backlight is supported

[firefly-linux-kernel-4.4.55.git] / drivers / platform / x86 / toshiba_acpi.c

diff --git a/drivers/platform/x86/toshiba_acpi.c b/drivers/platform/x86/toshiba_acpi.c
index c01302989ee47817eb37acac36755c63dd0b262c..b0f62141ea4d975fe65cc26d892fd494190235bd 100644 (file)
--- a/drivers/platform/x86/toshiba_acpi.c
+++ b/drivers/platform/x86/toshiba_acpi.c
@@ -2484,6 +2484,14 @@ static int toshiba_acpi_setup_backlight(struct toshiba_acpi_dev *dev)
        brightness = __get_lcd_brightness(dev);
        if (brightness < 0)
                return 0;
+       /*
+        * If transflective backlight is supported and the brightness is zero
+        * (lowest brightness level), the set_lcd_brightness function will
+        * activate the transflective backlight, making the LCD appear to be
+        * turned off, simply increment the brightness level to avoid that.
+        */
+       if (dev->tr_backlight_supported && brightness == 0)
+               brightness++;
        ret = set_lcd_brightness(dev, brightness);
        if (ret) {
                pr_debug("Backlight method is read-only, disabling backlight support\n");