[PATCH] fbdev: Remove software clipping from drawing functions

Remove software clipping from imageblit, fillrect and copyarea.  Clipping is
not needed because the console layer assures that reads/writes doest not
happen beyond the extents of the framebuffer.  And software clipping tends to
hide bugs, if they do exist.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

drivers/video/cfbcopyarea.c

@@ -349,46 +349,10 @@ void cfb_copyarea(struct fb_info *p, const struct fb_copyarea *area)
 	unsigned long __iomem *dst = NULL, *src = NULL;
 	int bits = BITS_PER_LONG, bytes = bits >> 3;
 	int dst_idx = 0, src_idx = 0, rev_copy = 0;
-	int x2, y2, vxres, vyres;
 
 	if (p->state != FBINFO_STATE_RUNNING)
 		return;
 
-	/* We want rotation but lack hardware to do it for us. */
-	if (!p->fbops->fb_rotate && p->var.rotate) {
-	}
-
-	vxres = p->var.xres_virtual;
-	vyres = p->var.yres_virtual;
-
-	if (area->dx > vxres || area->sx > vxres ||
-	    area->dy > vyres || area->sy > vyres)
-		return;
-
-	/* clip the destination
-	 * We could use hardware clipping but on many cards you get around
-	 * hardware clipping by writing to framebuffer directly.
-	 */
-	x2 = area->dx + area->width;
-	y2 = area->dy + area->height;
-	dx = area->dx > 0 ? area->dx : 0;
-	dy = area->dy > 0 ? area->dy : 0;
-	x2 = x2 < vxres ? x2 : vxres;
-	y2 = y2 < vyres ? y2 : vyres;
-	width = x2 - dx;
-	height = y2 - dy;
-
-	if ((width==0) ||(height==0))
-		return;
-
-	/* update sx1,sy1 */
-	sx += (dx - area->dx);
-	sy += (dy - area->dy);
-
-	/* the source must be completely inside the virtual screen */
-	if (sx < 0 || sy < 0 || (sx + width) > vxres || (sy + height) > vyres)
-		return;
-
 	/* if the beginning of the target area might overlap with the end of
 	the source area, be have to copy the area reverse. */
 	if ((dy == sy && dx > sx) || (dy > sy)) {

drivers/video/cfbfillrect.c

@@ -344,7 +344,8 @@ bitfill_unaligned_rev(unsigned long __iomem *dst, int dst_idx, unsigned long pat
 
 void cfb_fillrect(struct fb_info *p, const struct fb_fillrect *rect)
 {
-	unsigned long x2, y2, vxres, vyres, height, width, pat, fg;
+	unsigned long pat, fg;
+	unsigned long width = rect->width, height = rect->height;
 	int bits = BITS_PER_LONG, bytes = bits >> 3;
 	u32 bpp = p->var.bits_per_pixel;
 	unsigned long __iomem *dst;
@@ -353,27 +354,6 @@ void cfb_fillrect(struct fb_info *p, const struct fb_fillrect *rect)
 	if (p->state != FBINFO_STATE_RUNNING)
 		return;
 
-	/* We want rotation but lack hardware to do it for us. */
-	if (!p->fbops->fb_rotate && p->var.rotate) {
-	}
-
-	vxres = p->var.xres_virtual;
-	vyres = p->var.yres_virtual;
-
-	if (!rect->width || !rect->height ||
-	    rect->dx > vxres || rect->dy > vyres)
-		return;
-
-	/* We could use hardware clipping but on many cards you get around
-	 * hardware clipping by writing to framebuffer directly. */
-
-	x2 = rect->dx + rect->width;
-	y2 = rect->dy + rect->height;
-	x2 = x2 < vxres ? x2 : vxres;
-	y2 = y2 < vyres ? y2 : vyres;
-	width = x2 - rect->dx;
-	height = y2 - rect->dy;
-
 	if (p->fix.visual == FB_VISUAL_TRUECOLOR ||
 	    p->fix.visual == FB_VISUAL_DIRECTCOLOR )
 		fg = ((u32 *) (p->pseudo_palette))[rect->color];

drivers/video/cfbimgblt.c

@@ -272,33 +272,13 @@ void cfb_imageblit(struct fb_info *p, const struct fb_image *image)
 {
 	u32 fgcolor, bgcolor, start_index, bitstart, pitch_index = 0;
 	u32 bpl = sizeof(u32), bpp = p->var.bits_per_pixel;
-	u32 width = image->width, height = image->height; 
+	u32 width = image->width;
 	u32 dx = image->dx, dy = image->dy;
-	int x2, y2, vxres, vyres;
 	u8 __iomem *dst1;
 
 	if (p->state != FBINFO_STATE_RUNNING)
 		return;
 
-	vxres = p->var.xres_virtual;
-	vyres = p->var.yres_virtual;
-	/* 
-	 * We could use hardware clipping but on many cards you get around
-	 * hardware clipping by writing to framebuffer directly like we are
-	 * doing here. 
-	 */
-	if (image->dx > vxres || image->dy > vyres)
-		return;
-
-	x2 = image->dx + image->width;
-	y2 = image->dy + image->height;
-	dx = image->dx > 0 ? image->dx : 0;
-	dy = image->dy > 0 ? image->dy : 0;
-	x2 = x2 < vxres ? x2 : vxres;
-	y2 = y2 < vyres ? y2 : vyres;
-	width  = x2 - dx;
-	height = y2 - dy;
-
 	bitstart = (dy * p->fix.line_length * 8) + (dx * bpp);
 	start_index = bitstart & (32 - 1);
 	pitch_index = (p->fix.line_length & (bpl - 1)) * 8;