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Commit 09a2910e authored by Krzysztof Helt's avatar Krzysztof Helt Committed by Linus Torvalds
Browse files

cirrusfb: check_par fixes 



1. Check if virtual resolution fits into memory.
   Otherwise, Linux hangs during panning.
2. When selected use all available memory to
    maximize yres_virtual to speed up panning
   (previously also xres_virtual was increased).
3. Simplify memory restriction calculations.

Signed-off-by: default avatarKrzysztof Helt <krzysztof.h1@poczta.fm>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 950bbabb

drivers/video/cirrusfb.c

+18 −41
Original line number Original line Diff line number Diff line
@@ -628,27 +628,18 @@ static long cirrusfb_get_mclk(long freq, int bpp, long *div) 
static int cirrusfb_check_var(struct fb_var_screeninfo *var,

static int cirrusfb_check_var(struct fb_var_screeninfo *var,

			      struct fb_info *info)

			      struct fb_info *info)

{

{

	int nom, den;		/* translyting from pixels->bytes */

	int yres;

	int yres, i;

	/* memory size in pixels */

	static struct { int xres, yres; } modes[] =

	unsigned pixels = info->screen_size * 8 / var->bits_per_pixel;

	{ { 1600, 1280 },

	  { 1280, 1024 },

	  { 1024, 768 },

	  { 800, 600 },

	  { 640, 480 },

	  { -1, -1 } };





	switch (var->bits_per_pixel) {

	switch (var->bits_per_pixel) {

	case 1:

	case 1:

		nom = 4;

		pixels /= 4;

		den = 8;

		break;		/* 8 pixel per byte, only 1/4th of mem usable */

		break;		/* 8 pixel per byte, only 1/4th of mem usable */

	case 8:

	case 8:

	case 16:

	case 16:

	case 24:

	case 24:

	case 32:

	case 32:

		nom = var->bits_per_pixel / 8;

		den = 1;

		break;		/* 1 pixel == 1 byte */

		break;		/* 1 pixel == 1 byte */

	default:

	default:

		printk(KERN_ERR "cirrusfb: mode %dx%dx%d rejected..."

		printk(KERN_ERR "cirrusfb: mode %dx%dx%d rejected..."
@@ -658,43 +649,29 @@ static int cirrusfb_check_var(struct fb_var_screeninfo *var, 
		return -EINVAL;

		return -EINVAL;

	}

	}





	if (var->xres * nom / den * var->yres > info->screen_size) {

	if (var->xres_virtual < var->xres)

		printk(KERN_ERR "cirrusfb: mode %dx%dx%d rejected..."

		var->xres_virtual = var->xres;

			"resolution too high to fit into video memory!\n",

			var->xres, var->yres, var->bits_per_pixel);

		DPRINTK("EXIT - EINVAL error\n");

		return -EINVAL;

	}



	/* use highest possible virtual resolution */

	/* use highest possible virtual resolution */

	if (var->xres_virtual == -1 &&

	if (var->yres_virtual == -1) {

	    var->yres_virtual == -1) {

		var->yres_virtual = pixels / var->xres_virtual;

		printk(KERN_INFO

		     "cirrusfb: using maximum available virtual resolution\n");

		for (i = 0; modes[i].xres != -1; i++) {

			int size = modes[i].xres * nom / den * modes[i].yres;

			if (size < info->screen_size / 2)

				break;

		}

		if (modes[i].xres == -1) {

			printk(KERN_ERR "cirrusfb: could not find a virtual "

				"resolution that fits into video memory!!\n");

			DPRINTK("EXIT - EINVAL error\n");

			return -EINVAL;

		}

		var->xres_virtual = modes[i].xres;

		var->yres_virtual = modes[i].yres;





		printk(KERN_INFO "cirrusfb: virtual resolution set to "

		printk(KERN_INFO "cirrusfb: virtual resolution set to "

			"maximum of %dx%d\n", var->xres_virtual,

			"maximum of %dx%d\n", var->xres_virtual,

			var->yres_virtual);

			var->yres_virtual);

	}

	}



	if (var->xres_virtual < var->xres)

		var->xres_virtual = var->xres;

	if (var->yres_virtual < var->yres)

	if (var->yres_virtual < var->yres)

		var->yres_virtual = var->yres;

		var->yres_virtual = var->yres;





	if (var->xres_virtual * var->yres_virtual > pixels) {

		printk(KERN_ERR "cirrusfb: mode %dx%dx%d rejected... "

		      "virtual resolution too high to fit into video memory!\n",

			var->xres_virtual, var->yres_virtual,

			var->bits_per_pixel);

		DPRINTK("EXIT - EINVAL error\n");

		return -EINVAL;

	}





	if (var->xoffset < 0)

	if (var->xoffset < 0)

		var->xoffset = 0;

		var->xoffset = 0;

	if (var->yoffset < 0)

	if (var->yoffset < 0)