x86: Don't check for BIOS corruption in first 64K when there's no nee…

…d to

Due to commit 781c5a6 it is
likely that the number of areas to scan for BIOS corruption is 0
 -- especially when the first 64K is already reserved
(X86_RESERVE_LOW is 64K by default).

If that's the case then don't set up the scan.

Signed-off-by: Naga Chumbalkar <nagananda.chumbalkar@hp.com>
Cc: <stable@kernel.org>
LKML-Reference: <20110225202838.2229.71011.sendpatchset@nchumbalkar.americas.hpqcorp.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/check.c

@@ -106,8 +106,8 @@ void __init setup_bios_corruption_check(void)
 		addr += size;
 	}
 
-	printk(KERN_INFO "Scanning %d areas for low memory corruption\n",
-	       num_scan_areas);
+	if (num_scan_areas)
+		printk(KERN_INFO "Scanning %d areas for low memory corruption\n", num_scan_areas);
 }
 
 
@@ -143,12 +143,12 @@ static void check_corruption(struct work_struct *dummy)
 {
 	check_for_bios_corruption();
 	schedule_delayed_work(&bios_check_work,
-		round_jiffies_relative(corruption_check_period*HZ)); 
+		round_jiffies_relative(corruption_check_period*HZ));
 }
 
 static int start_periodic_check_for_corruption(void)
 {
-	if (!memory_corruption_check || corruption_check_period == 0)
+	if (!num_scan_areas || !memory_corruption_check || corruption_check_period == 0)
 		return 0;
 
 	printk(KERN_INFO "Scanning for low memory corruption every %d seconds\n",