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;