[PATCH] vesafb: Drop blank hook

From: Bugzilla Bug 5351

"After resuming from S3 (suspended while in X), the LCD panel stays black .
 However, the laptop is up again, and I can SSH into it from another
machine.

I can get the panel working again, when I first direct video output to the
CRT output of the laptop, and then back to LCD (done by repeatedly hitting
Fn+F5 buttons on the Toshiba, which directs output to either LCD, CRT or
TV) None of this ever happened with older kernels."

This bug is due to the recently added vesafb_blank() method in vesafb.  It
works with CRT displays, but has a high incidence of problems in laptop
users.  Since CRT users don't really get that much benefit from hardware
blanking, drop support for this.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

arch/i386/boot/video.S

@@ -97,7 +97,6 @@
 #define PARAM_VESAPM_OFF	0x30
 #define PARAM_LFB_PAGES		0x32
 #define PARAM_VESA_ATTRIB	0x34
-#define PARAM_CAPABILITIES      0x36
 
 /* Define DO_STORE according to CONFIG_VIDEO_RETAIN */
 #ifdef CONFIG_VIDEO_RETAIN
@@ -234,10 +233,6 @@ mopar_gr:
 	movw	18(%di), %ax
 	movl	%eax, %fs:(PARAM_LFB_SIZE)
 
-# store mode capabilities
-	movl    10(%di), %eax
-	movl    %eax, %fs:(PARAM_CAPABILITIES)
-
 # switching the DAC to 8-bit is for <= 8 bpp only
 	movw	%fs:(PARAM_LFB_DEPTH), %ax
 	cmpw	$8, %ax

drivers/video/vesafb.c

@@ -57,7 +57,6 @@ static unsigned short  *pmi_base  = NULL;
 static void            (*pmi_start)(void);
 static void            (*pmi_pal)(void);
 static int             depth;
-static int             vga_compat;
 
 /* --------------------------------------------------------------------- */
 
@@ -90,37 +89,6 @@ static int vesafb_pan_display(struct fb_var_screeninfo *var,
 	return 0;
 }
 
-static int vesafb_blank(int blank, struct fb_info *info)
-{
-	int err = 1;
-
-	if (vga_compat) {
-		int loop = 10000;
-		u8 seq = 0, crtc17 = 0;
-
-		if (blank == FB_BLANK_POWERDOWN) {
-			seq = 0x20;
-			crtc17 = 0x00;
-			err = 0;
-		} else {
-			seq = 0x00;
-			crtc17 = 0x80;
-			err = (blank == FB_BLANK_UNBLANK) ? 0 : -EINVAL;
-		}
-
-		vga_wseq(NULL, 0x00, 0x01);
-		seq |= vga_rseq(NULL, 0x01) & ~0x20;
-		vga_wseq(NULL, 0x00, seq);
-
-		crtc17 |= vga_rcrt(NULL, 0x17) & ~0x80;
-		while (loop--);
-		vga_wcrt(NULL, 0x17, crtc17);
-		vga_wseq(NULL, 0x00, 0x03);
-	}
-
-	return err;
-}
-
 static void vesa_setpalette(int regno, unsigned red, unsigned green,
 			    unsigned blue)
 {
@@ -205,7 +173,6 @@ static struct fb_ops vesafb_ops = {
 	.owner		= THIS_MODULE,
 	.fb_setcolreg	= vesafb_setcolreg,
 	.fb_pan_display	= vesafb_pan_display,
-	.fb_blank       = vesafb_blank,
 	.fb_fillrect	= cfb_fillrect,
 	.fb_copyarea	= cfb_copyarea,
 	.fb_imageblit	= cfb_imageblit,
@@ -459,10 +426,6 @@ static int __init vesafb_probe(struct platform_device *dev)
 	info->flags = FBINFO_FLAG_DEFAULT |
 		(ypan) ? FBINFO_HWACCEL_YPAN : 0;
 
-	vga_compat = (screen_info.capabilities & 2) ? 0 : 1;
-	printk("vesafb: Mode is %sVGA compatible\n",
-	       (vga_compat) ? "" : "not ");
-
 	if (fb_alloc_cmap(&info->cmap, 256, 0) < 0) {
 		err = -ENOMEM;
 		goto err;

include/linux/screen_info.h

@@ -41,8 +41,7 @@ struct screen_info {
 	u16 vesapm_off;		/* 0x30 */
 	u16 pages;		/* 0x32 */
 	u16 vesa_attributes;	/* 0x34 */
-	u32  capabilities;      /* 0x36 */
-				/* 0x3a -- 0x3f reserved for future expansion */
+				/* 0x36 -- 0x3f reserved for future expansion */
 };
 
 extern struct screen_info screen_info;