diff --git a/arch/x86_64/kernel/pmtimer.c b/arch/x86_64/kernel/pmtimer.c
index bf421ed..7554458 100644
--- a/arch/x86_64/kernel/pmtimer.c
+++ b/arch/x86_64/kernel/pmtimer.c
@@ -27,7 +27,7 @@
 /* The I/O port the PMTMR resides at.
  * The location is detected during setup_arch(),
  * in arch/i386/kernel/acpi/boot.c */
-u32 pmtmr_ioport;
+u32 pmtmr_ioport __read_mostly;
 
 /* value of the Power timer at last timer interrupt */
 static u32 offset_delay;
diff --git a/drivers/clocksource/acpi_pm.c b/drivers/clocksource/acpi_pm.c
index 9217be5..066dc77 100644
--- a/drivers/clocksource/acpi_pm.c
+++ b/drivers/clocksource/acpi_pm.c
@@ -30,7 +30,7 @@
  * The location is detected during setup_arch(),
  * in arch/i386/acpi/boot.c
  */
-u32 pmtmr_ioport;
+u32 pmtmr_ioport __read_mostly;
 
 #define ACPI_PM_MASK 0xFFFFFF /* limit it to 24 bits */
 
@@ -47,7 +47,7 @@ static cycle_t acpi_pm_read_verified(void)
 	/*
 	 * It has been reported that because of various broken
 	 * chipsets (ICH4, PIIX4 and PIIX4E) where the ACPI PM clock
-	 * source is not latched, so you must read it multiple
+	 * source is not latched, you must read it multiple
 	 * times to ensure a safe value is read:
 	 */
 	do {