diff options
| author | Christian Svensson <bluecmd@google.com> | 2019-07-01 17:26:17 +0100 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2019-07-01 17:28:59 +0100 |
| commit | 055762479be1575377ecf2d8fceb9d8df2703d0f (patch) | |
| tree | f93e04303fc7da74f8889a600dd358518849163f /hw/timer | |
| parent | 696942b8bc6562a2b23c6ed8ae32ecdeb9bf4b60 (diff) | |
aspeed/timer: Ensure positive muldiv delta
If the host decrements the counter register that results in a negative
delta. This is then passed to muldiv64 which only handles unsigned
numbers resulting in bogus results.
This fix ensures the delta being operated on is positive.
Test case: kexec a kernel using aspeed_timer and it will freeze on the
second bootup when the kernel initializes the timer. With this patch
that no longer happens and the timer appears to run OK.
Signed-off-by: Christian Svensson <bluecmd@google.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Message-id: 20190618165311.27066-12-clg@kaod.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'hw/timer')
| -rw-r--r-- | hw/timer/aspeed_timer.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/hw/timer/aspeed_timer.c b/hw/timer/aspeed_timer.c index 745eb8608b..29cc5e8070 100644 --- a/hw/timer/aspeed_timer.c +++ b/hw/timer/aspeed_timer.c @@ -275,7 +275,11 @@ static void aspeed_timer_set_value(AspeedTimerCtrlState *s, int timer, int reg, int64_t delta = (int64_t) value - (int64_t) calculate_ticks(t, now); uint32_t rate = calculate_rate(t); - t->start += muldiv64(delta, NANOSECONDS_PER_SECOND, rate); + if (delta >= 0) { + t->start += muldiv64(delta, NANOSECONDS_PER_SECOND, rate); + } else { + t->start -= muldiv64(-delta, NANOSECONDS_PER_SECOND, rate); + } aspeed_timer_mod(t); } break; |