Friendly ping.
Is this an effective bugfix?
On 2020/7/17 17:21, Keqian Zhu wrote:
> ARM virtual counter supports event stream. It can only trigger an event
> when the trigger bit of CNTVCT_EL0 changes from 0 to 1 (or from 1 to 0),
> so the actual period of event stream is 2 ^ (cntkctl_evnti + 1). For
> example, when the trigger bit is 0, then it triggers an event for every
> two cycles.
>
> Signed-off-by: Keqian Zhu <zhukeqian1@xxxxxxxxxx>
> ---
> drivers/clocksource/arm_arch_timer.c | 17 ++++++++++++++---
> 1 file changed, 14 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
> index ecf7b7db2d05..06d99a4b1b9b 100644
> --- a/drivers/clocksource/arm_arch_timer.c
> +++ b/drivers/clocksource/arm_arch_timer.c
> @@ -799,10 +799,20 @@ static void __arch_timer_setup(unsigned type,
> static void arch_timer_evtstrm_enable(int divider)
> {
> u32 cntkctl = arch_timer_get_cntkctl();
> + int cntkctl_evnti;
> +
> + /*
> + * Note that it can only trigger an event when the trigger bit
> + * of CNTVCT_EL0 changes from 1 to 0 (or from 0 to 1), so the
> + * actual period of event stream is 2 ^ (cntkctl_evnti + 1).
> + */
> + cntkctl_evnti = divider - 1;
> + cntkctl_evnti = min(cntkctl_evnti, 15);
> + cntkctl_evnti = max(cntkctl_evnti, 0);
>
> cntkctl &= ~ARCH_TIMER_EVT_TRIGGER_MASK;
> /* Set the divider and enable virtual event stream */
> - cntkctl |= (divider << ARCH_TIMER_EVT_TRIGGER_SHIFT)
> + cntkctl |= (cntkctl_evnti << ARCH_TIMER_EVT_TRIGGER_SHIFT)
> | ARCH_TIMER_VIRT_EVT_EN;
> arch_timer_set_cntkctl(cntkctl);
> arch_timer_set_evtstrm_feature();
> @@ -816,10 +826,11 @@ static void arch_timer_configure_evtstream(void)
> /* Find the closest power of two to the divisor */
> evt_stream_div = arch_timer_rate / ARCH_TIMER_EVT_STREAM_FREQ;
> pos = fls(evt_stream_div);
> - if (pos > 1 && !(evt_stream_div & (1 << (pos - 2))))
> + if ((pos == 1) || (pos > 1 && !(evt_stream_div & (1 << (pos - 2)))))
> pos--;
> +
> /* enable event stream */
> - arch_timer_evtstrm_enable(min(pos, 15));
> + arch_timer_evtstrm_enable(pos);
> }
>
> static void arch_counter_set_user_access(void)
>
