+static int uvesafb_blank(int blank, struct fb_info *info)
+{
+	struct uvesafb_par *par = info->par;
+	struct uvesafb_ktask *task;
+	int err = 1;
+
+	if (par->vbe_ib.capabilities & VBE_CAP_VGACOMPAT) {
+		int loop = 10000;
+		u8 seq = 0, crtc17 = 0;
+
+		if (blank == FB_BLANK_POWERDOWN) {
+			seq = 0x20;
+			crtc17 = 0x00;
+			err = 0;
+		} else {
+			seq = 0x00;
+			crtc17 = 0x80;
+			err = (blank == FB_BLANK_UNBLANK) ? 0 : -EINVAL;
+		}
+
+		vga_wseq(NULL, 0x00, 0x01);
+		seq |= vga_rseq(NULL, 0x01) & ~0x20;
+		vga_wseq(NULL, 0x00, seq);
+
+		crtc17 |= vga_rcrt(NULL, 0x17) & ~0x80;
+		while (loop--);
+		vga_wcrt(NULL, 0x17, crtc17);
+		vga_wseq(NULL, 0x00, 0x03);
+	} else {
+		task = uvesafb_prep();
+		if (!task)
+			return -ENOMEM;
+
+		task->t.regs.eax = 0x4f10;
+		switch (blank) {
+		case FB_BLANK_UNBLANK:
+			task->t.regs.ebx = 0x0001;
+			break;
+		case FB_BLANK_NORMAL:
+			task->t.regs.ebx = 0x0101;	/* standby */
+			break;
+		case FB_BLANK_POWERDOWN:
+			task->t.regs.ebx = 0x0401;	/* powerdown */
+			break;
+		default:
+			goto out;
+		}
+		task->t.flags = 0;
+
+		err = uvesafb_exec(task);
+		if (!err && (task->t.regs.eax & 0xffff) == 0x004f)
+			err = 0;

There is no effect to this assignment.

	if (!err && ... )
		err = 0;

+out:		uvesafb_free(task);
+	}
+	return err;
+}

[...]

+static int __devinit uvesafb_init(void)
+{
+	int err;
+
+#ifndef MODULE
+	char *option = NULL;
+
+	if (fb_get_options("uvesafb", &option))
+		return -ENODEV;
+	uvesafb_setup(option);
+#endif
+	err = cn_add_callback(&uvesafb_cn_id, "uvesafb", uvesafb_cn_callback);
+	if (err)
+		goto err_out;
+
+	err = platform_driver_register(&uvesafb_driver);
+
+	if (!err) {
+		uvesafb_device = platform_device_alloc("uvesafb", 0);
+		if (uvesafb_device)
+			err = platform_device_add(uvesafb_device);
+		else
+			err = -ENOMEM;
+
+		if (err) {
+			platform_device_put(uvesafb_device);
+			platform_driver_unregister(&uvesafb_driver);

Initialization failed. It should return from this function here.
Otherwise it will attempt to call driver_create_file() with unregistered
driver below.

And you forgot to put:
			cn_del_callback(&uvesafb_cn_id);

+		}
+
+		err = driver_create_file(&uvesafb_driver.driver,
+				&driver_attr_v86d);
+		if (err) {
+			printk(KERN_WARNING "uvesafb: failed to register "
+					"attributes\n");
+			err = 0;
+		}
+	}
+	return err;
+
+err_out:
+	if (nls && nls->sk_socket)
+		sock_release(nls->sk_socket);

I can't find any uses of nls in this driver.

+	return err;
+}