[PATCH] savagefb: X-panning fixes

The driver unconditionally sets xpanstep to 2.  However, a value of 4
empirically works better at bpp = 8, and 2 for 16 and 32.  This buglet was
exposed by the rotation code.

Second fix is the unconditional call to update_start() without verifying if
the offsets are correct.  Remove this call, it's not necessary and secondly,
it causes a crash with invalid values.
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/savage/savagefb_driver.c

@@ -1315,10 +1315,14 @@ static void savagefb_set_fix(struct fb_info *info)
 	info->fix.line_length = info->var.xres_virtual *
 		info->var.bits_per_pixel / 8;
 
-	if (info->var.bits_per_pixel == 8)
+	if (info->var.bits_per_pixel == 8) {
 		info->fix.visual      = FB_VISUAL_PSEUDOCOLOR;
-	else
+		info->fix.xpanstep    = 4;
+	} else {
 		info->fix.visual      = FB_VISUAL_TRUECOLOR;
+		info->fix.xpanstep    = 2;
+	}
+
 }
 
 #if defined(CONFIG_FB_SAVAGE_ACCEL)
@@ -1363,7 +1367,6 @@ static int savagefb_set_par (struct fb_info *info)
 	par->minClock = 10000;
 
 	savagefb_set_par_int (par);
-	savagefb_update_start (par, var);
 	fb_set_cmap (&info->cmap, info);
 	savagefb_set_fix(info);
 	savagefb_set_clip(info);
@@ -1873,7 +1876,6 @@ static int __devinit savage_init_fb_info (struct fb_info *info,
 
 	info->fix.type	   = FB_TYPE_PACKED_PIXELS;
 	info->fix.type_aux	   = 0;
-	info->fix.xpanstep	   = 2;
 	info->fix.ypanstep	   = 1;
 	info->fix.ywrapstep   = 0;
 	info->fix.accel       = id->driver_data;