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-rw-r--r--vl.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/vl.c b/vl.c
index 3ad3625b62..deff1496ef 100644
--- a/vl.c
+++ b/vl.c
@@ -1305,11 +1305,14 @@ static void hpet_stop_timer(struct qemu_alarm_timer *t)
static int rtc_start_timer(struct qemu_alarm_timer *t)
{
int rtc_fd;
+ unsigned long current_rtc_freq = 0;
TFR(rtc_fd = open("/dev/rtc", O_RDONLY));
if (rtc_fd < 0)
return -1;
- if (ioctl(rtc_fd, RTC_IRQP_SET, RTC_FREQ) < 0) {
+ ioctl(rtc_fd, RTC_IRQP_READ, &current_rtc_freq);
+ if (current_rtc_freq != RTC_FREQ &&
+ ioctl(rtc_fd, RTC_IRQP_SET, RTC_FREQ) < 0) {
fprintf(stderr, "Could not configure '/dev/rtc' to have a 1024 Hz timer. This is not a fatal\n"
"error, but for better emulation accuracy either use a 2.6 host Linux kernel or\n"
"type 'echo 1024 > /proc/sys/dev/rtc/max-user-freq' as root.\n");