Messages in this thread Patch in this message | | | From | Vincent Chen <> | Subject | [PATCH] [RFC PATCH v1] clocksource: entend the max_delta_ns of timer-riscv andtimer-clint to ULONG_MAX | Date | Tue, 8 Aug 2023 12:51:45 +0800 |
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From: Vincentc Chen <vincent.chen@sifive.com>
When registering the riscv-timer or clint-timer as a clock_event device, the driver needs to specify the value of max_delta_ticks. This value directly influences the max_delta_ns, which signifies the maximum time interval for configuring subsequent clock events. Currently, both riscv-timer and clint-timer are set with a max_delta_ticks value of 0x7fff_ffff. When the timer operates at a high frequency, such as 1GHz, this causes the system only can sleep for a short time. For the 1GHz case, the sleep cannot exceed two seconds. To address this limitation, refer to other timer implementations to extend it to 2^(bit-width of the timer) - 1. Because the bit-width of $mtimecmp is 64bit, so this value becomes ULONG_MAX (0xffff_ffff_ffff_ffff).
Signed-off-by: Vincentc Chen <vincent.chen@sifive.com> --- drivers/clocksource/timer-clint.c | 2 +- drivers/clocksource/timer-riscv.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/clocksource/timer-clint.c b/drivers/clocksource/timer-clint.c index 9a55e733ae99..09fd292eb83d 100644 --- a/drivers/clocksource/timer-clint.c +++ b/drivers/clocksource/timer-clint.c @@ -131,7 +131,7 @@ static int clint_timer_starting_cpu(unsigned int cpu) struct clock_event_device *ce = per_cpu_ptr(&clint_clock_event, cpu); ce->cpumask = cpumask_of(cpu); - clockevents_config_and_register(ce, clint_timer_freq, 100, 0x7fffffff); + clockevents_config_and_register(ce, clint_timer_freq, 100, ULONG_MAX); enable_percpu_irq(clint_timer_irq, irq_get_trigger_type(clint_timer_irq)); diff --git a/drivers/clocksource/timer-riscv.c b/drivers/clocksource/timer-riscv.c index da3071b387eb..b25c91d41968 100644 --- a/drivers/clocksource/timer-riscv.c +++ b/drivers/clocksource/timer-riscv.c @@ -94,7 +94,7 @@ static int riscv_timer_starting_cpu(unsigned int cpu) ce->irq = riscv_clock_event_irq; if (riscv_timer_cannot_wake_cpu) ce->features |= CLOCK_EVT_FEAT_C3STOP; - clockevents_config_and_register(ce, riscv_timebase, 100, 0x7fffffff); + clockevents_config_and_register(ce, riscv_timebase, 100, ULONG_MAX); enable_percpu_irq(riscv_clock_event_irq, irq_get_trigger_type(riscv_clock_event_irq)); -- 2.34.1
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