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[PULL 7/8] mos6522: update counters when timer interrupts are off


From: David Gibson
Subject: [PULL 7/8] mos6522: update counters when timer interrupts are off
Date: Tue, 26 Nov 2019 17:01:50 +1100

From: Laurent Vivier <address@hidden>

Even if the interrupts are off, counters must be updated because
they are running anyway and kernel can try to read them
(it's the case with g3beige kernel).

Reported-by: Andrew Randrianasulu <address@hidden>
Signed-off-by: Laurent Vivier <address@hidden>
Message-Id: <address@hidden>
Reviewed-by: Philippe Mathieu-Daudé <address@hidden>
Signed-off-by: David Gibson <address@hidden>
---
 hw/misc/mos6522.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/hw/misc/mos6522.c b/hw/misc/mos6522.c
index aa3bfe1afd..cecf0be59e 100644
--- a/hw/misc/mos6522.c
+++ b/hw/misc/mos6522.c
@@ -113,6 +113,10 @@ static int64_t get_next_irq_time(MOS6522State *s, 
MOS6522Timer *ti,
     int64_t d, next_time;
     unsigned int counter;
 
+    if (ti->frequency == 0) {
+        return INT64_MAX;
+    }
+
     /* current counter value */
     d = muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) - ti->load_time,
                  ti->frequency, NANOSECONDS_PER_SECOND);
@@ -149,10 +153,10 @@ static void mos6522_timer1_update(MOS6522State *s, 
MOS6522Timer *ti,
     if (!ti->timer) {
         return;
     }
+    ti->next_irq_time = get_next_irq_time(s, ti, current_time);
     if ((s->ier & T1_INT) == 0 || (s->acr & T1MODE) != T1MODE_CONT) {
         timer_del(ti->timer);
     } else {
-        ti->next_irq_time = get_next_irq_time(s, ti, current_time);
         timer_mod(ti->timer, ti->next_irq_time);
     }
 }
@@ -163,10 +167,10 @@ static void mos6522_timer2_update(MOS6522State *s, 
MOS6522Timer *ti,
     if (!ti->timer) {
         return;
     }
+    ti->next_irq_time = get_next_irq_time(s, ti, current_time);
     if ((s->ier & T2_INT) == 0) {
         timer_del(ti->timer);
     } else {
-        ti->next_irq_time = get_next_irq_time(s, ti, current_time);
         timer_mod(ti->timer, ti->next_irq_time);
     }
 }
-- 
2.23.0




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