Subject: [PATCH] [acpi video] Add helper to determine the bus POST options

- Add video_bus_post_options() that executes _VPO, if can_post() is true.
- Set ->v_post_options with returned value, so we can use it later
- Add #defines for bit masks of that value
- Call when device is added, so we can know the options later on

Signed-off-by: Patrick Mochel <mochel@linux.intel.com>

---

 drivers/acpi/drivers/video/bus-device.c |   57 +++++++++++++++++++++++++++++++
 drivers/acpi/drivers/video/bus-driver.c |    1 +
 drivers/acpi/drivers/video/video.h      |    7 ++++
 3 files changed, 65 insertions(+), 0 deletions(-)

applies-to: 49899495eb804f1acf39bc4fa417e4a3ef069fac
80b0077373b86e9f14020c002fa822e5e4a2988e
diff --git a/drivers/acpi/drivers/video/bus-device.c b/drivers/acpi/drivers/video/bus-device.c
index 60d9564..10f125e 100644
--- a/drivers/acpi/drivers/video/bus-device.c
+++ b/drivers/acpi/drivers/video/bus-device.c
@@ -30,6 +30,16 @@ static int is_handle(struct acpi_dev * a
 }
 
 
+static int get_int(struct acpi_dev * ad, char * obj, unsigned long * val)
+{
+	acpi_status status;
+
+	status = acpi_evaluate_integer(ad->acpi_device->handle,
+				       obj, NULL, val);
+	return ACPI_SUCCESS(status) ? 0 : -ENODEV;
+}
+
+
 /**
  *	can_switch - Check if a video bus supports video switching
  *	@ad:	The ACPI device representing the video bus
@@ -116,3 +126,50 @@ void video_bus_check(struct acpi_video_b
 	if (can_post(vb->v_ad))
 		vb->v_can_post = 1;
 }
+
+
+/**
+ *	video_bus_post_options - Query the POST options of the bus
+ *	@vb:	The ACPI video bus
+ *
+ *	If the device is capable of POSTing, then get the integer mask 
+ *	stored at _VPO, which will tell us what devices it is capable of 
+ *	executing the POST on.
+ *
+ *	The device should always be capable of posting the on-board video,
+ *	but apparently the BIOS may incorrectly tell us that it cannot.
+ *	Do a sanity check of this and give the user an ominous message
+ *	if it doesn't hold true.
+ *
+ *	NOTE: The original driver masked the returned value with '3', but
+ *	later checked e.g.
+ *		if (options & 4) ...
+ *	Assuming that we want to keep that bit, the mask has changed to 0x7.
+ */
+
+int video_bus_post_options(struct acpi_video_bus * vb)
+{
+	unsigned long o;
+	int ret = 0;
+
+	if (can_post(vb->v_ad)) {
+		ret = get_int(vb->v_ad, "_VPO", &o);
+
+		if (!ret) {
+			vb->v_post_options = o & 0x7;
+
+			/*
+			 * Make sure integrated video can post.
+			 * Warn user if it cannot.
+			 */
+			if (!(o & ACPI_VIDEO_BUS_POST_INTEGRATED)) {
+				err("The motherboard VGA device is not");
+				err("listed as a possible POST device.");
+				err("This indicate a BIOS bug.");
+				err("Please contact the manufacturer.");
+				err("options = %#01lx", o);
+			}
+		}
+	}
+	return ret;
+}
diff --git a/drivers/acpi/drivers/video/bus-driver.c b/drivers/acpi/drivers/video/bus-driver.c
index efd9492..c49417d 100644
--- a/drivers/acpi/drivers/video/bus-driver.c
+++ b/drivers/acpi/drivers/video/bus-driver.c
@@ -28,6 +28,7 @@ static int video_bus_add(struct acpi_dev
 	av->v_ad = ad;
 
 	video_bus_check(av);
+	video_bus_post_options(av);
 
 	dev_set_drvdata(&ad->dev, av);
 
diff --git a/drivers/acpi/drivers/video/video.h b/drivers/acpi/drivers/video/video.h
index e1e2d5b..ff2eac8 100644
--- a/drivers/acpi/drivers/video/video.h
+++ b/drivers/acpi/drivers/video/video.h
@@ -12,14 +12,21 @@
 ACPI_MODULE_NAME("acpi_video");
 
 
+#define ACPI_VIDEO_BUS_POST_INTEGRATED	0x01
+#define ACPI_VIDEO_BUS_POST_PCI		0x02
+#define ACPI_VIDEO_BUS_POST_AGP		0x04
+
 struct acpi_video_bus {
 	int			v_can_switch;
 	int			v_has_rom;
 	int			v_can_post;
 
+	int			v_post_options;
+
 	struct acpi_dev		* v_ad;
 };
 
 extern int video_bus_test(struct acpi_dev * ad);
 
 extern void video_bus_check(struct acpi_video_bus * vb);
+int video_bus_post_options(struct acpi_video_bus * vb);
---
0.99.9.GIT