The BookE decrementer stops at 0, meaning that it won't decremented towards "negative" values. However, the current logic is inverted: decr is updated solely when the resulting value would be negative.
Signed-off-by: Clément Chigot <chi...@adacore.com> Fixed: 8e0a5ac87800 ("hw/ppc: Avoid decrementer rounding errors") --- hw/ppc/ppc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/hw/ppc/ppc.c b/hw/ppc/ppc.c index e6fa5580c0..9fc85c7de0 100644 --- a/hw/ppc/ppc.c +++ b/hw/ppc/ppc.c @@ -729,7 +729,9 @@ static inline int64_t __cpu_ppc_load_decr(CPUPPCState *env, int64_t now, int64_t decr; n = ns_to_tb(tb_env->decr_freq, now); - if (next > n && tb_env->flags & PPC_TIMER_BOOKE) { + + /* BookE timers stop when reaching 0. */ + if (next < n && tb_env->flags & PPC_TIMER_BOOKE) { decr = 0; } else { decr = next - n; -- 2.25.1