1 files changed, 58 insertions, 2 deletions

diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
index 45d8097ef4cf..b728880ef10e 100644
--- a/drivers/acpi/video_detect.c
+++ b/drivers/acpi/video_detect.c
@@ -132,6 +132,33 @@ find_video(acpi_handle handle, u32 lvl, void *context, void **rv)
         return AE_OK;
 }
 
+/* Force to use vendor driver when the ACPI device is known to be
+ * buggy */
+static int video_detect_force_vendor(const struct dmi_system_id *d)
+{
+        acpi_video_support |= ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
+        return 0;
+}
+
+static struct dmi_system_id video_detect_dmi_table[] = {
+        /* On Samsung X360, the BIOS will set a flag (VDRV) if generic
+         * ACPI backlight device is used. This flag will definitively break
+         * the backlight interface (even the vendor interface) untill next
+         * reboot. It's why we should prevent video.ko from being used here
+         * and we can't rely on a later call to acpi_video_unregister().
+         */
+        {
+         .callback = video_detect_force_vendor,
+         .ident = "X360",
+         .matches = {
+                DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
+                DMI_MATCH(DMI_PRODUCT_NAME, "X360"),
+                DMI_MATCH(DMI_BOARD_NAME, "X360"),
+                },
+        },
+        { },
+};
+
 /*
  * Returns the video capabilities of a specific ACPI graphics device
  *
@@ -164,6 +191,8 @@ long acpi_video_get_capabilities(acpi_handle graphics_handle)
                  *              ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
                  *}
                  */
+
+                dmi_check_system(video_detect_dmi_table);
         } else {
                 status = acpi_bus_get_device(graphics_handle, &tmp_dev);
                 if (ACPI_FAILURE(status)) {
@@ -182,8 +211,7 @@ long acpi_video_get_capabilities(acpi_handle graphics_handle)
 }
 EXPORT_SYMBOL(acpi_video_get_capabilities);
 
-/* Returns true if video.ko can do backlight switching */
-int acpi_video_backlight_support(void)
+static void acpi_video_caps_check(void)
 {
         /*
          * We must check whether the ACPI graphics device is physically plugged
@@ -191,6 +219,34 @@ int acpi_video_backlight_support(void)
          */
         if (!acpi_video_caps_checked)
                 acpi_video_get_capabilities(NULL);
+}
+
+/* Promote the vendor interface instead of the generic video module.
+ * This function allow DMI blacklists to be implemented by externals
+ * platform drivers instead of putting a big blacklist in video_detect.c
+ * After calling this function you will probably want to call
+ * acpi_video_unregister() to make sure the video module is not loaded
+ */
+void acpi_video_dmi_promote_vendor(void)
+{
+        acpi_video_caps_check();
+        acpi_video_support |= ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
+}
+EXPORT_SYMBOL(acpi_video_dmi_promote_vendor);
+
+/* To be called when a driver who previously promoted the vendor
+ * interface */
+void acpi_video_dmi_demote_vendor(void)
+{
+        acpi_video_caps_check();
+        acpi_video_support &= ~ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
+}
+EXPORT_SYMBOL(acpi_video_dmi_demote_vendor);
+
+/* Returns true if video.ko can do backlight switching */
+int acpi_video_backlight_support(void)
+{
+        acpi_video_caps_check();
 
         /* First check for boot param -> highest prio */
         if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR)