diff options
Diffstat (limited to 'drivers/clocksource/timer-imx-tpm.c')
| -rw-r--r-- | drivers/clocksource/timer-imx-tpm.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/drivers/clocksource/timer-imx-tpm.c b/drivers/clocksource/timer-imx-tpm.c index bd64a8a8427f..92c025b70eb6 100644 --- a/drivers/clocksource/timer-imx-tpm.c +++ b/drivers/clocksource/timer-imx-tpm.c @@ -83,20 +83,28 @@ static u64 notrace tpm_read_sched_clock(void) static int tpm_set_next_event(unsigned long delta, struct clock_event_device *evt) { - unsigned long next, now; + unsigned long next, prev, now; - next = tpm_read_counter(); - next += delta; + prev = tpm_read_counter(); + next = prev + delta; writel(next, timer_base + TPM_C0V); now = tpm_read_counter(); /* + * Need to wait CNT increase at least 1 cycle to make sure + * the C0V has been updated into HW. + */ + if ((next & 0xffffffff) != readl(timer_base + TPM_C0V)) + while (now == tpm_read_counter()) + ; + + /* * NOTE: We observed in a very small probability, the bus fabric * contention between GPU and A7 may results a few cycles delay * of writing CNT registers which may cause the min_delta event got * missed, so we need add a ETIME check here in case it happened. */ - return (int)(next - now) <= 0 ? -ETIME : 0; + return (now - prev) >= delta ? -ETIME : 0; } static int tpm_set_state_oneshot(struct clock_event_device *evt) |