[Qemu-devel] [PATCH 3/4] hw/ds1338: Remove 'now' field from state struct

[Peter Maydell <peter.maydell@linaro.org>]

The 'struct tm now' field in the state structure is in fact only
ever used as a temporary (the actual RTC state is held in 'offset').
Remove it from the state structure in favour of using local variables
to avoid confusion about whether it needs to be saved on migration.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/ds1338.c |   41 +++++++++++++++++++++--------------------
 1 file changed, 21 insertions(+), 20 deletions(-)

diff --git a/hw/ds1338.c b/hw/ds1338.c
index 842d2de..16aba4b 100644
--- a/hw/ds1338.c
+++ b/hw/ds1338.c
@@ -20,7 +20,6 @@
 typedef struct {
     I2CSlave i2c;
     time_t offset;
-    struct tm now;
     uint8_t nvram[NVRAM_SIZE];
     int ptr;
     int addr_byte;
@@ -31,21 +30,22 @@ static void capture_current_time(DS1338State *s)
     /* Capture the current time into the secondary registers
      * which will be actually read by the data transfer operation.
      */
-    qemu_get_timedate(&s->now, s->offset);
-    s->nvram[0] = to_bcd(s->now.tm_sec);
-    s->nvram[1] = to_bcd(s->now.tm_min);
+    struct tm now;
+    qemu_get_timedate(&now, s->offset);
+    s->nvram[0] = to_bcd(now.tm_sec);
+    s->nvram[1] = to_bcd(now.tm_min);
     if (s->nvram[2] & 0x40) {
-        s->nvram[2] = (to_bcd((s->now.tm_hour % 12)) + 1) | 0x40;
-        if (s->now.tm_hour >= 12) {
+        s->nvram[2] = (to_bcd((now.tm_hour % 12)) + 1) | 0x40;
+        if (now.tm_hour >= 12) {
             s->nvram[2] |= 0x20;
         }
     } else {
-        s->nvram[2] = to_bcd(s->now.tm_hour);
+        s->nvram[2] = to_bcd(now.tm_hour);
     }
-    s->nvram[3] = to_bcd(s->now.tm_wday) + 1;
-    s->nvram[4] = to_bcd(s->now.tm_mday);
-    s->nvram[5] = to_bcd(s->now.tm_mon) + 1;
-    s->nvram[6] = to_bcd(s->now.tm_year - 100);
+    s->nvram[3] = to_bcd(now.tm_wday) + 1;
+    s->nvram[4] = to_bcd(now.tm_mday);
+    s->nvram[5] = to_bcd(now.tm_mon) + 1;
+    s->nvram[6] = to_bcd(now.tm_year - 100);
 }
 
 static void inc_regptr(DS1338State *s)
@@ -100,14 +100,15 @@ static int ds1338_send(I2CSlave *i2c, uint8_t data)
         return 0;
     }
     if (s->ptr < 8) {
-        qemu_get_timedate(&s->now, s->offset);
+        struct tm now;
+        qemu_get_timedate(&now, s->offset);
         switch(s->ptr) {
         case 0:
             /* TODO: Implement CH (stop) bit.  */
-            s->now.tm_sec = from_bcd(data & 0x7f);
+            now.tm_sec = from_bcd(data & 0x7f);
             break;
         case 1:
-            s->now.tm_min = from_bcd(data & 0x7f);
+            now.tm_min = from_bcd(data & 0x7f);
             break;
         case 2:
             if (data & 0x40) {
@@ -119,25 +120,25 @@ static int ds1338_send(I2CSlave *i2c, uint8_t data)
             } else {
                 data = from_bcd(data);
             }
-            s->now.tm_hour = data;
+            now.tm_hour = data;
             break;
         case 3:
-            s->now.tm_wday = from_bcd(data & 7) - 1;
+            now.tm_wday = from_bcd(data & 7) - 1;
             break;
         case 4:
-            s->now.tm_mday = from_bcd(data & 0x3f);
+            now.tm_mday = from_bcd(data & 0x3f);
             break;
         case 5:
-            s->now.tm_mon = from_bcd(data & 0x1f) - 1;
+            now.tm_mon = from_bcd(data & 0x1f) - 1;
             break;
         case 6:
-            s->now.tm_year = from_bcd(data) + 100;
+            now.tm_year = from_bcd(data) + 100;
             break;
         case 7:
             /* Control register. Currently ignored.  */
             break;
         }
-        s->offset = qemu_timedate_diff(&s->now);
+        s->offset = qemu_timedate_diff(&now);
     } else {
         s->nvram[s->ptr] = data;
     }
-- 
1.7.9.5