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author | Laurent Vivier <lvivier@redhat.com> | 2015-08-24 19:29:45 +0200 |
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committer | Laurent Vivier <lvivier@redhat.com> | 2015-09-25 14:53:29 +0200 |
commit | 37b9ab92f7f8295c61daa4a8893eb8fb1add63e2 (patch) | |
tree | 92c9a4c83231fdd65ae066f4571fcd9e1cba2ce2 /hw/smbios | |
parent | 9491e9bc019a365dfa9780f462984a0d052f4c0d (diff) |
rtl8139: 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/smbios')
0 files changed, 0 insertions, 0 deletions