diff options
author | Laurent Vivier <lvivier@redhat.com> | 2015-08-04 10:27:31 +0200 |
---|---|---|
committer | Michael Tokarev <mjt@tls.msk.ru> | 2015-09-11 10:21:38 +0300 |
commit | fee562e9e41290a22623de83b673a8929ec5280d (patch) | |
tree | 77fcffdf9d062bdb50bd4bb6ad417002f532ab1d /hw/watchdog/wdt_i6300esb.c | |
parent | 6883de6c9b647d5629ffe131ed5d97c06bb0db1a (diff) |
i6300esb: fix timer overflow
We use muldiv64() to compute the time to wait:
timeout = muldiv64(get_ticks_per_sec(), timeout, 33000000);
but get_ticks_per_sec() is 10^9 (30 bit value) and timeout
is a 35 bit value.
Whereas muldiv64 is:
uint64_t muldiv64(uint64_t a, uint32_t b, uint32_t c)
So we loose 3 bits of timeout.
Swapping get_ticks_per_sec() and timeout fixes it.
We can also replace it by a multiplication by 30 ns,
but this changes PCI clock frequency from 33MHz to 33.333333MHz
and we need to do this on all the QEMU PCI devices (later...)
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Diffstat (limited to 'hw/watchdog/wdt_i6300esb.c')
-rw-r--r-- | hw/watchdog/wdt_i6300esb.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/hw/watchdog/wdt_i6300esb.c b/hw/watchdog/wdt_i6300esb.c index cfa2b1be13..3e07d44878 100644 --- a/hw/watchdog/wdt_i6300esb.c +++ b/hw/watchdog/wdt_i6300esb.c @@ -136,7 +136,7 @@ static void i6300esb_restart_timer(I6300State *d, int stage) * multiply here can exceed 64-bits, before we divide by 33MHz, so * we use a higher-precision intermediate result. */ - timeout = muldiv64(get_ticks_per_sec(), timeout, 33000000); + timeout = muldiv64(timeout, get_ticks_per_sec(), 33000000); i6300esb_debug("stage %d, timeout %" PRIi64 "\n", d->stage, timeout); |