[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 d0b4880..2d793d4 100644 (file)
--- 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) {