CC [M]  drivers/acpi/video.o
drivers/acpi/video.c:398:12: error: redefinition of ‘video_ignore_initial_backlight’
drivers/acpi/video.c:392:12: note: previous definition of ‘video_ignore_initial_backlight’ was here
drivers/acpi/video.c:392:12: warning: ‘video_ignore_initial_backlight’ defined but not used [-Wunused-function]

diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index 0230cb6..e1975f5 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -389,6 +389,12 @@ static int __init video_set_bqc_offset(const struct dmi_system_id *d)
    return 0;
 }
 
+static int video_ignore_initial_backlight(const struct dmi_system_id *d)
+{
+   use_bios_initial_backlight = 0;
+   return 0;
+}
+
 static struct dmi_system_id video_dmi_table[] __initdata = {
    /*
     * Broken _BQC workaround http://bugzilla.kernel.org/show_bug.cgi?id=13121
@@ -433,6 +439,14 @@ static struct dmi_system_id video_dmi_table[] __initdata = {
       DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 7720"),
       },
    },
+   {
+    .callback = video_ignore_initial_backlight,
+    .ident = "HP Folio 13-2000",
+    .matches = {
+      DMI_MATCH(DMI_BOARD_VENDOR, "Hewlett-Packard"),
+      DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13 - 2000 Notebook PC"),
+      },
+   },
    {}
 };
 
@@ -567,8 +581,14 @@ acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
    video->dos_setting = arg0.integer.value;
    status = acpi_evaluate_object(video->device->handle, "_DOS",
       &args, NULL);
-   if (ACPI_FAILURE(status))
-      return -EIO;
+   if (ACPI_FAILURE(status)) {
+      /*
+       * some platforms don't have _DOS, but the ACPI
+       * backlight control still works
+       */
+      ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _DOS\n"));
+      return 0;
+   }
 
    return 0;
 }