hw/rtc/goldfish: keep time offset when resetting

Currently resetting the leads to resynchronizing the Goldfish RTC
with the system clock of the host. In real hardware an RTC reset
would not change the wall time. Other RTCs like pl031 do not show
this behavior.

Move the synchronization of the RTC with the system clock to the
instance realization.

Cc: qemu-stable@nongnu.org
Reported-by: Frederik Du Toit Lotter <fred.lotter@canonical.com>
Fixes: 9a5b40b8427 ("hw: rtc: Add Goldfish RTC device")
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20250321221248.17764-1-heinrich.schuchardt@canonical.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
(cherry picked from commit 2542d5cf471a38c4ceb9717708178938b96ded47)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

diff --git a/hw/rtc/goldfish_rtc.c b/hw/rtc/goldfish_rtc.c
index 3dcf307e992902a95fe68856c27c2796a9296c36..75d4cb0f31682da5e0c49ba578ad031f24ff76bb 100644 (file)
--- a/hw/rtc/goldfish_rtc.c
+++ b/hw/rtc/goldfish_rtc.c
@@ -239,15 +239,8 @@ static const VMStateDescription goldfish_rtc_vmstate = {
 static void goldfish_rtc_reset(DeviceState *dev)
 {
     GoldfishRTCState *s = GOLDFISH_RTC(dev);
-    struct tm tm;
 
     timer_del(s->timer);
-
-    qemu_get_timedate(&tm, 0);
-    s->tick_offset = mktimegm(&tm);
-    s->tick_offset *= NANOSECONDS_PER_SECOND;
-    s->tick_offset -= qemu_clock_get_ns(rtc_clock);
-    s->tick_offset_vmstate = 0;
     s->alarm_next = 0;
     s->alarm_running = 0;
     s->irq_pending = 0;
@@ -258,6 +251,7 @@ static void goldfish_rtc_realize(DeviceState *d, Error **errp)
 {
     SysBusDevice *dev = SYS_BUS_DEVICE(d);
     GoldfishRTCState *s = GOLDFISH_RTC(d);
+    struct tm tm;
 
     memory_region_init_io(&s->iomem, OBJECT(s),
                           &goldfish_rtc_ops[s->big_endian], s,
@@ -267,6 +261,11 @@ static void goldfish_rtc_realize(DeviceState *d, Error **errp)
     sysbus_init_irq(dev, &s->irq);
 
     s->timer = timer_new_ns(rtc_clock, goldfish_rtc_interrupt, s);
+
+    qemu_get_timedate(&tm, 0);
+    s->tick_offset = mktimegm(&tm);
+    s->tick_offset *= NANOSECONDS_PER_SECOND;
+    s->tick_offset -= qemu_clock_get_ns(rtc_clock);
 }
 
 static Property goldfish_rtc_properties[] = {