diff options
| -rw-r--r-- | hw/sbe-p9.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/hw/sbe-p9.c b/hw/sbe-p9.c index d6bc577..362ef54 100644 --- a/hw/sbe-p9.c +++ b/hw/sbe-p9.c @@ -100,6 +100,14 @@ struct lock sbe_timer_lock; #define SBE_TIMER_DEFAULT_US 500 static uint64_t sbe_timer_def_tb; +/* + * Rate limit continuous timer update. + * We can update inflight timer if new timer request is lesser than inflight + * one. Limit such updates so that SBE gets time to handle FIFO side requests. + */ +#define SBE_TIMER_UPDATE_MAX 2 +static uint32_t timer_update_cnt = 0; + /* Timer control message */ static struct p9_sbe_msg *timer_ctrl_msg; @@ -539,6 +547,15 @@ static void p9_sbe_timer_response(struct p9_sbe *sbe) sbe_timer_in_progress = false; /* Drop lock and call timers */ unlock(&sbe->lock); + + lock(&sbe_timer_lock); + /* + * Once we get timer expiry interrupt (even if its suprious interrupt) + * we can schedule next timer request. + */ + timer_update_cnt = 0; + unlock(&sbe_timer_lock); + check_timers(true); lock(&sbe->lock); } @@ -800,6 +817,11 @@ static void p9_sbe_timer_schedule(void) return; } + /* Stop sending timer update chipop until inflight timer expires */ + if (timer_update_cnt > SBE_TIMER_UPDATE_MAX) + return; + timer_update_cnt++; + if (now < sbe_timer_target) { /* Calculate how many microseconds from now, rounded up */ if ((sbe_timer_target - now) > sbe_timer_def_tb) { |