From: Jordan Crouse <jordan.crouse@amd.com>
Date: Fri, 6 Jan 2006 08:12:16 +0000 (-0800)
Subject: [PATCH] APM Screen Blanking fix
X-Git-Tag: v2.6.16-rc1~936^2~180
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3841b0a173cb6fc52163e67c03280543f2412db3;p=linux-2.6

[PATCH] APM Screen Blanking fix

- Fix screen blanking on BIOSes that return APM_NOT_ENGAGED when APM enabled
  screen blanking is not turned on.

  The original code only tried to set the state on device 0x100, and then
  0x1FF, and I added 0x101 to the mix too.

- Clean up logic in apm_console_blank().

- Prevent the error message from printing out twice.

Cc: Jordan Crouse <jordan.crouse@amd.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/arch/i386/kernel/apm.c b/arch/i386/kernel/apm.c
index d0b488056c..2d793d4aef 100644
--- a/arch/i386/kernel/apm.c
+++ b/arch/i386/kernel/apm.c
@@ -1064,22 +1064,23 @@ static int apm_engage_power_management(u_short device, int enable)
  
 static int apm_console_blank(int blank)
 {
-	int	error;
-	u_short	state;
+	int error, i;
+	u_short state;
+	static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
 
 	state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
-	/* Blank the first display device */
-	error = set_power_state(0x100, state);
-	if ((error != APM_SUCCESS) && (error != APM_NO_ERROR)) {
-		/* try to blank them all instead */
-		error = set_power_state(0x1ff, state);
-		if ((error != APM_SUCCESS) && (error != APM_NO_ERROR))
-			/* try to blank device one instead */
-			error = set_power_state(0x101, state);
+
+	for (i = 0; i < ARRAY_SIZE(dev); i++) {
+		error = set_power_state(dev[i], state);
+
+		if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
+			return 1;
+
+		if (error == APM_NOT_ENGAGED)
+			break;
 	}
-	if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
-		return 1;
-	if (error == APM_NOT_ENGAGED) {
+
+	if (error == APM_NOT_ENGAGED && state != APM_STATE_READY) {
 		static int tried;
 		int eng_error;
 		if (tried++ == 0) {