[PATCH] fbdev: split vesafb option vram into vtotal and vremap

From: Gerd Knorr <kraxel@bytesex.org>:

"IMHO the the only sane thing is to have two options for total + remapped
memory as well.  Otherwise we'll end up changing that back and forth like
it happened for the size calculation stuff for quite some time ...

The patch below does just that and also has the other vmode fix
(vmode = yres * linelength /* instead of yres * xres * depth >> 3 */)."
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Documentation/fb/vesafb.txt

@@ -146,11 +146,16 @@ pmipal	Use the protected mode interface for palette changes.
 
 mtrr	setup memory type range registers for the vesafb framebuffer.
 
-vram:n	remap 'n' MiB of video RAM. If 0 or not specified, remap memory
+vremap:n
+        remap 'n' MiB of video RAM. If 0 or not specified, remap memory
 	according to video mode. (2.5.66 patch/idea by Antonino Daplas
 	reversed to give override possibility (allocate more fb memory
 	than the kernel would) to 2.4 by tmb@iki.fi)
 
+vtotal:n
+        if the video BIOS of your card incorrectly determines the total
+        amount of video RAM, use this option to override the BIOS (in MiB).
+
 Have fun!
 
   Gerd

drivers/video/vesafb.c

@@ -49,7 +49,8 @@ static struct fb_fix_screeninfo vesafb_fix __initdata = {
 
 static int             inverse   = 0;
 static int             mtrr      = 1;
-static int	       vram __initdata = 0; /* Set amount of memory to be used */
+static int	       vram_remap __initdata = 0; /* Set amount of memory to be used */
+static int	       vram_total __initdata = 0; /* Set total amount of memory */
 static int             pmi_setpal = 0;	/* pmi for palette changes ??? */
 static int             ypan       = 0;  /* 0..nothing, 1..ypan, 2..ywrap */
 static unsigned short  *pmi_base  = NULL;
@@ -209,8 +210,10 @@ int __init vesafb_setup(char *options)
 			mtrr=1;
 		else if (! strcmp(this_opt, "nomtrr"))
 			mtrr=0;
-		else if (! strncmp(this_opt, "vram:", 5))
-			vram = simple_strtoul(this_opt+5, NULL, 0);
+		else if (! strncmp(this_opt, "vtotal:", 7))
+			vram_total = simple_strtoul(this_opt+7, NULL, 0);
+		else if (! strncmp(this_opt, "vremap:", 7))
+			vram_remap = simple_strtoul(this_opt+7, NULL, 0);
 	}
 	return 0;
 }
@@ -240,11 +243,14 @@ static int __init vesafb_probe(struct device *device)
 	/*   size_vmode -- that is the amount of memory needed for the
 	 *                 used video mode, i.e. the minimum amount of
 	 *                 memory we need. */
-	size_vmode = vesafb_fix.line_length * vesafb_defined.yres;
+	size_vmode = vesafb_defined.yres * vesafb_fix.line_length;
 
 	/*   size_total -- all video memory we have. Used for mtrr
-	 *                 entries and bounds checking. */
+	 *                 entries, ressource allocation and bounds
+	 *                 checking. */
 	size_total = screen_info.lfb_size * 65536;
+	if (vram_total)
+		size_total = vram_total * 1024 * 1024;
 	if (size_total < size_vmode)
 		size_total = size_vmode;
 
@@ -252,10 +258,11 @@ static int __init vesafb_probe(struct device *device)
 	 *                 use for vesafb.  With modern cards it is no
 	 *                 option to simply use size_total as that
 	 *                 wastes plenty of kernel address space. */
-	size_remap = size_vmode * 2;
-	if (vram)
-		size_remap = vram * 1024 * 1024;
-
+	size_remap  = size_vmode * 2;
+	if (vram_remap)
+		size_remap = vram_remap * 1024 * 1024;
+	if (size_remap < size_vmode)
+		size_remap = size_vmode;
 	if (size_remap > size_total)
 		size_remap = size_total;
 	vesafb_fix.smem_len = size_remap;