| Message ID | 1443190150-17312-4-git-send-email-lvivier@redhat.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/hw/net/pcnet.c b/hw/net/pcnet.c index 3437376..0eb3cc4 100644 --- a/hw/net/pcnet.c +++ b/hw/net/pcnet.c @@ -670,8 +670,7 @@ static inline hwaddr pcnet_rdra_addr(PCNetState *s, int idx) static inline int64_t pcnet_get_next_poll_time(PCNetState *s, int64_t current_time) { int64_t next_time = current_time + - muldiv64(65536 - (CSR_SPND(s) ? 0 : CSR_POLL(s)), - get_ticks_per_sec(), 33000000L); + (65536 - (CSR_SPND(s) ? 0 : CSR_POLL(s))) * 30; if (next_time <= current_time) next_time = current_time + 1; return next_time;
Originally, timers were ticks based, and it made sense to add ticks to current time to know when to trigger an alarm. But since commit: 7447545 change all other clock references to use nanosecond resolution accessors All timers use nanoseconds and we need to convert ticks to nanoseconds, by doing something like: y = muldiv64(x, get_ticks_per_sec(), PCI_FREQUENCY) where x is the number of device ticks and y the number of system ticks. y is used as nanoseconds in timer functions, it works because 1 tick is 1 nanosecond. (get_ticks_per_sec() is 10^9) But as PCI frequency is 33 MHz, we can also do: y = x * 30; /* 33 MHz PCI period is 30 ns */ Which is much more simple. This implies a 33.333333 MHz PCI frequency, but this is correct. Signed-off-by: Laurent Vivier <lvivier@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> --- hw/net/pcnet.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)