Index: uspace/drv/time/cmos-rtc/cmos-regs.h
===================================================================
--- uspace/drv/time/cmos-rtc/cmos-regs.h	(revision 1170ea3c5243d093b1a8827f7c31e5ebffec6ddb)
+++ uspace/drv/time/cmos-rtc/cmos-regs.h	(revision cf729431e2d328dcd1fd95a1f692c33d72b93030)
@@ -38,12 +38,12 @@
 
 #define RTC_STATUS_B    0x0B
-#define RTC_MASK_24H    0x02
-#define RTC_MASK_BCD    0x04
+#define RTC_MASK_24H    0x02 /* 24h mode */
+#define RTC_MASK_BCD    0x04 /* BCD mode */
 
 #define RTC_STATUS_D    0x0D
-#define RTC_BATTERY_OK  0x80
+#define RTC_BATTERY_OK  0x80 /* Battery status */
 
-#define RTC_UPDATE      0x0A
-#define RTC_MASK_UPDATE 0x08
+#define RTC_STATUS_A    0x0A
+#define RTC_MASK_UPDATE 0x80 /* Update in progress */
 
 #endif
Index: uspace/drv/time/cmos-rtc/cmos-rtc.c
===================================================================
--- uspace/drv/time/cmos-rtc/cmos-rtc.c	(revision 1170ea3c5243d093b1a8827f7c31e5ebffec6ddb)
+++ uspace/drv/time/cmos-rtc/cmos-rtc.c	(revision cf729431e2d328dcd1fd95a1f692c33d72b93030)
@@ -275,5 +275,5 @@
 rtc_update_in_progress(rtc_t *rtc)
 {
-	return rtc_register_read(rtc, RTC_UPDATE) & RTC_MASK_UPDATE;
+	return rtc_register_read(rtc, RTC_STATUS_A) & RTC_MASK_UPDATE;
 }