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authorLaurent Vivier <lvivier@redhat.com>2015-08-24 19:29:45 +0200
committerLaurent Vivier <lvivier@redhat.com>2015-09-25 14:53:50 +0200
commitc6acbe861f1ed4203f4864baf756686064ba561f (patch)
tree8a1026f7f6cd9310668d2e0774a15d7b668660fa /hw
parent37b9ab92f7f8295c61daa4a8893eb8fb1add63e2 (diff)
pcnet: remove muldiv64()
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>
Diffstat (limited to 'hw')
-rw-r--r--hw/net/pcnet.c3
1 files changed, 1 insertions, 2 deletions
diff --git a/hw/net/pcnet.c b/hw/net/pcnet.c
index 34373767d9..0eb3cc4d5b 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;