Subject: [PATCH] [acpi video] Cache video bus capabilities

- Add video_bus_check() that checks for familiar methods in
  device's namespace (the same as video_bus_test()).
- Break out checks for each capability into their own 1-line helpers
  and update video_bus_test().
- If a bus supports each, set a flag in struct acpi_video_bus.
- Call video_bus_check() and print bus capabilities when device is bound.

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

---

 drivers/acpi/drivers/video/bus-device.c |   88 ++++++++++++++++++++++++-------
 drivers/acpi/drivers/video/bus-driver.c |    9 ++-
 drivers/acpi/drivers/video/video.h      |    6 ++
 3 files changed, 81 insertions(+), 22 deletions(-)

applies-to: eacc8fd705f55f35b250b298cda818175c0b6ac4
69413b3a8214d2a5f9cd86e0f5fdfcf55a28f396
diff --git a/drivers/acpi/drivers/video/bus-device.c b/drivers/acpi/drivers/video/bus-device.c
index 7a11dda..60d9564 100644
--- a/drivers/acpi/drivers/video/bus-device.c
+++ b/drivers/acpi/drivers/video/bus-device.c
@@ -31,6 +31,49 @@ static int is_handle(struct acpi_dev * a
 
 
 /**
+ *	can_switch - Check if a video bus supports video switching
+ *	@ad:	The ACPI device representing the video bus
+ *
+ *	Determine if bus support switching by checking for availability
+ *	of _DOD and _DOS.
+ */
+
+static int can_switch(struct acpi_dev * ad)
+{
+	return (is_handle(ad, "_DOD") && is_handle(ad, "_DOS"));
+}
+
+
+/**
+ *	has_rom - Check if a video bus has an attached ROM
+ *	@ad:	The ACPI device representing the video bus
+ *
+ *	Determine if bus has a ROM bus by checking for _ROM.
+ */
+
+static int has_rom(struct acpi_dev * ad)
+{
+	return is_handle(ad, "_ROM");
+}
+
+
+/**
+ *	can_post - Check if a video bus can configure device to POST
+ *	@ad:	The ACPI device representing the video bus
+ *
+ *	Determine if bus supports POST configuration by checking for 
+ *	_GPD, _SPD and _VPD.
+ */
+
+static int can_post(struct acpi_dev * ad)
+{
+	return (is_handle(ad, "_VPD") && 
+		is_handle(ad, "_GPD") &&
+		is_handle(ad, "_SPD"));
+}
+
+
+/**
  *	video_bus_test - Check device to see if it's a video bus
  *	@ad:	The ACPI device that we're checking
  *
@@ -47,24 +90,29 @@ static int is_handle(struct acpi_dev * a
 
 int video_bus_test(struct acpi_dev * ad)
 {
-	/*
-	 * Video switching
-	 */
-	if (is_handle(ad, "_DOD") && is_handle(ad, "_DOS"))
-		return 1;
-
-	/*
-	 * ROM retrieval
-	 */
-	if (is_handle(ad, "_ROM"))
-		return 1;
-
-	/*
-	 * POST configuration
-	 */
-	if (is_handle(ad, "_VPD") && 
-	    is_handle(ad, "_GPD") &&
-	    is_handle(ad, "_SPD"))
-		return 1;
-	return 0;
+	return (can_switch(ad) || has_rom(ad) || can_post(ad));
+}
+
+
+
+/**
+ *	video_bus_check - Determine a bus's capabilities
+ *	@vb:	The ACPI video device to check
+ *
+ *	This does the same checks as video_bus_test(), but it always
+ *	runs all of the checks, so it can set the flags. And, we now
+ *	have a struct acpi_video_bus with which we can cache the 
+ *	values..
+ */
+
+void video_bus_check(struct acpi_video_bus * vb)
+{
+	if (can_switch(vb->v_ad))
+		vb->v_can_switch = 1;
+
+	if (has_rom(vb->v_ad))
+		vb->v_has_rom = 1;
+
+	if (can_post(vb->v_ad))
+		vb->v_can_post = 1;
 }
diff --git a/drivers/acpi/drivers/video/bus-driver.c b/drivers/acpi/drivers/video/bus-driver.c
index 2e0202a..efd9492 100644
--- a/drivers/acpi/drivers/video/bus-driver.c
+++ b/drivers/acpi/drivers/video/bus-driver.c
@@ -27,10 +27,15 @@ static int video_bus_add(struct acpi_dev
 
 	av->v_ad = ad;
 
+	video_bus_check(av);
+
 	dev_set_drvdata(&ad->dev, av);
 
-	printk(KERN_INFO PREFIX "video bus [%s]\n",
-	       acpi_dev_bid(ad));
+	printk(KERN_INFO PREFIX "video bus [%s] : %s %s %s\n",
+	       acpi_dev_bid(ad),
+	       av->v_can_switch ? "multi-head" : "",
+	       av->v_has_rom ? "rom" : "",
+	       av->v_can_post ? "post" : "");
 	return 0;
 }
 
diff --git a/drivers/acpi/drivers/video/video.h b/drivers/acpi/drivers/video/video.h
index 78f3a2a..e1e2d5b 100644
--- a/drivers/acpi/drivers/video/video.h
+++ b/drivers/acpi/drivers/video/video.h
@@ -13,7 +13,13 @@ ACPI_MODULE_NAME("acpi_video");
 
 
 struct acpi_video_bus {
+	int			v_can_switch;
+	int			v_has_rom;
+	int			v_can_post;
+
 	struct acpi_dev		* v_ad;
 };
 
 extern int video_bus_test(struct acpi_dev * ad);
+
+extern void video_bus_check(struct acpi_video_bus * vb);
---
0.99.9.GIT