[ 3.5.y.z extended stable ] Patch "acpi/video_detect: blacklist samsung x360" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    acpi/video_detect: blacklist samsung x360

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From c0633598c686f6f76dd41c66937d77e538227d30 Mon Sep 17 00:00:00 2001
From: Corentin Chary <corentin.chary at gmail.com>
Date: Wed, 13 Jun 2012 09:32:04 +0200
Subject: [PATCH] acpi/video_detect: blacklist samsung x360

commit 084940d5b101e9ca91a689eb5048151b14076839 upstream.

On Samsung X360, the BIOS will set a flag (VDRV) if the 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().

Signed-off-by: Corentin Chary <corentin.chary at gmail.com>
Signed-off-by: Matthew Garrett <mjg at redhat.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/acpi/video_detect.c | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
index 45d8097..841bfde 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)) {
--
1.8.1.2