+ neofb-fix-unblank-logic-interfering-with-lid-toggled-backlight.patch added to -mm tree

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



The patch titled

     neofb: fix unblank logic interfering with lid toggled backlight

has been added to the -mm tree.  Its filename is

     neofb-fix-unblank-logic-interfering-with-lid-toggled-backlight.patch

See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this

------------------------------------------------------
Subject: neofb: fix unblank logic interfering with lid toggled backlight
From: Christian Trefzer <ctrefzer@xxxxxx>


This is a fix for the most annoying problem that remained with neofb:

After "setterm -powersave powerdown" the console blanker will disable the
backlight after the given timeout expires.  If this happens after the lid
has been shut, we read "LCD off" from the register and store that in the
driver.  Once the lid is opened, the backlight turns on, but any key press
that would awaken the blanked console will switch the backlight off again.

The workaround so far was to use the "display config toggle" Fn key combo -
once if no external display is attached, otherwise as often as required to
restore the desired display setup.

The following patch fixes the issue at least for the LCD-only case, with no
external monitor attached.  Other display setup permutations are pending
further testing, but so far I can guarantee at least no negative change in
behaviour, if any at all.

Signed-off-by: Christian Trefzer <ctrefzer@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---

 drivers/video/neofb.c |   32 +++++++++++++++++++++++---------
 1 file changed, 23 insertions(+), 9 deletions(-)

diff -puN drivers/video/neofb.c~neofb-fix-unblank-logic-interfering-with-lid-toggled-backlight drivers/video/neofb.c
--- devel/drivers/video/neofb.c~neofb-fix-unblank-logic-interfering-with-lid-toggled-backlight	2006-06-03 16:43:43.000000000 -0700
+++ devel-akpm/drivers/video/neofb.c	2006-06-03 16:43:43.000000000 -0700
@@ -1333,17 +1333,22 @@ static int neofb_blank(int blank_mode, s
 	 *  run "setterm -powersave powerdown" to take advantage
 	 */
 	struct neofb_par *par = info->par;
-	int seqflags, lcdflags, dpmsflags, reg;
-
+	int seqflags, lcdflags, dpmsflags, reg, tmpdisp;
 
 	/*
-	 * Reload the value stored in the register, if sensible. It might have
-	 * been changed via FN keystroke.
+	 * Read back the register bits related to display configuration. They might
+	 * have been changed underneath the driver via Fn key stroke.
+	 */
+	neoUnlock();
+	tmpdisp = vga_rgfx(NULL, 0x20) & 0x03;
+	neoLock(&par->state);
+
+	/* In case we blank the screen, we want to store the possibly new
+	 * configuration in the driver. During un-blank, we re-apply this setting,
+	 * since the LCD bit will be cleared in order to switch off the backlight.
 	 */
 	if (par->PanelDispCntlRegRead) {
-		neoUnlock();
-		par->PanelDispCntlReg1 = vga_rgfx(NULL, 0x20) & 0x03;
-		neoLock(&par->state);
+		par->PanelDispCntlReg1 = tmpdisp;
 	}
 	par->PanelDispCntlRegRead = !blank_mode;
 
@@ -1378,12 +1383,21 @@ static int neofb_blank(int blank_mode, s
 		break;
 	case FB_BLANK_NORMAL:		/* just blank screen (backlight stays on) */
 		seqflags = VGA_SR01_SCREEN_OFF;	/* Disable sequencer */
-		lcdflags = par->PanelDispCntlReg1 & 0x02; /* LCD normal */
+		/*
+		 * During a blank operation with the LID shut, we might store "LCD off"
+		 * by mistake. Due to timing issues, the BIOS may switch the lights
+		 * back on, and we turn it back off once we "unblank".
+		 *
+		 * So here is an attempt to implement ">=" - if we are in the process
+		 * of unblanking, and the LCD bit is unset in the driver but set in the
+		 * register, we must keep it.
+		 */
+		lcdflags = ((par->PanelDispCntlReg1 | tmpdisp) & 0x02); /* LCD normal */
 		dpmsflags = 0x00;	/* no hsync/vsync suppression */
 		break;
 	case FB_BLANK_UNBLANK:		/* unblank */
 		seqflags = 0;			/* Enable sequencer */
-		lcdflags = par->PanelDispCntlReg1 & 0x02; /* LCD normal */
+		lcdflags = ((par->PanelDispCntlReg1 | tmpdisp) & 0x02); /* LCD normal */
 		dpmsflags = 0x00;	/* no hsync/vsync suppression */
 #ifdef CONFIG_TOSHIBA
 		/* Do we still need this ? */
_

Patches currently in -mm which might be from ctrefzer@xxxxxx are

neofb-fix-unblank-logic-interfering-with-lid-toggled-backlight.patch

-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Kernel Newbies FAQ]     [Kernel Archive]     [IETF Annouce]     [DCCP]     [Netdev]     [Networking]     [Security]     [Bugtraq]     [Photo]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux SCSI]

  Powered by Linux