[PATCH 1/1: 2.6.15-rc6] Fix framebuffer console upside-down ywrap scrolling

[PATCH 1/1: 2.6.15-rc6] Fix framebuffer console upside-down ywrap scrolling

[Knut Petersen]

Whenever ywrap scrolling is selected together with 180 degree
screen rotation, 2.6.15-rc6 and earlier versions are broken. 
fb_pan_display() expects non-negative yoffsets, but
ud_update_start() calls it with yoffsets down to -(yres - font height).
This patch transforms yoffset to the correct range 0 ... vyres-1.

Some obviously unneeded parentheses are removed, too.

Verified with cyblafb, should be applied before 2.6.15-final
because  it does fix the framebuffer rotation code introduced
early in the 2.6.15 release cycle.

Signed-off-by: Knut Petersen <Knut_Petersen@t-online.de>

diff -uprN -X linux/Documentation/dontdiff -x '*.bak' -x '*.ctx' linuxorig/drivers/video/console/fbcon_ud.c linux/drivers/video/console/fbcon_ud.c
--- linuxorig/drivers/video/console/fbcon_ud.c	2005-12-15 10:34:06.000000000 +0100
+++ linux/drivers/video/console/fbcon_ud.c	2005-12-20 06:59:19.000000000 +0100
@@ -420,13 +420,15 @@ static void ud_cursor(struct vc_data *vc
 int ud_update_start(struct fb_info *info)
 {
 	struct fbcon_ops *ops = info->fbcon_par;
-	u32 xoffset, yoffset;
+	int xoffset, yoffset;
 	u32 vyres = GETVYRES(ops->p->scrollmode, info);
 	u32 vxres = GETVXRES(ops->p->scrollmode, info);
 	int err;
 
-	xoffset = (vxres - info->var.xres) - ops->var.xoffset;
-	yoffset = (vyres - info->var.yres) - ops->var.yoffset;
+	xoffset = vxres - info->var.xres - ops->var.xoffset;
+	yoffset = vyres - info->var.yres - ops->var.yoffset;
+	if (yoffset < 0)
+		yoffset += vyres;
 	ops->var.xoffset = xoffset;
 	ops->var.yoffset = yoffset;
 	err = fb_pan_display(info, &ops->var);




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Re: [PATCH 1/1: 2.6.15-rc6] Fix framebuffer console upside-down ywrap scrolling

[Antonino A. Daplas]

Knut Petersen wrote:
> Whenever ywrap scrolling is selected together with 180 degree
> screen rotation, 2.6.15-rc6 and earlier versions are broken.
> fb_pan_display() expects non-negative yoffsets, but
> ud_update_start() calls it with yoffsets down to -(yres - font height).
> This patch transforms yoffset to the correct range 0 ... vyres-1.
> 
> Some obviously unneeded parentheses are removed, too.
> 
> Verified with cyblafb, should be applied before 2.6.15-final
> because  it does fix the framebuffer rotation code introduced
> early in the 2.6.15 release cycle.
> 
> Signed-off-by: Knut Petersen <Knut_Petersen@t-online.de>
Acked-by: Antonino Daplas <adaplas@pol.net>


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