[ACPI] properly detect pmtimer on ASUS a8v motherboard

[karo-tx-linux.git] / arch / i386 / kernel / acpi / boot.c

diff --git a/arch/i386/kernel/acpi/boot.c b/arch/i386/kernel/acpi/boot.c
index 76b1135d401a6eb3b4851fe344fe6f052f70300f..447fa9e33ffbeaaca7bbee58621900cbf0ba2b1e 100644 (file)
--- a/arch/i386/kernel/acpi/boot.c
+++ b/arch/i386/kernel/acpi/boot.c
@@ -638,6 +638,13 @@ static int __init acpi_parse_fadt(unsigned long phys, unsigned long size)
                        return 0;
 
                pmtmr_ioport = fadt->xpm_tmr_blk.address;
+               /*
+                * "X" fields are optional extensions to the original V1.0
+                * fields, so we must selectively expand V1.0 fields if the
+                * corresponding X field is zero.
+                */
+               if (!pmtmr_ioport)
+                       pmtmr_ioport = fadt->V1_pm_tmr_blk;
        } else {
                /* FADT rev. 1 */
                pmtmr_ioport = fadt->V1_pm_tmr_blk;