clocksource/drivers/tegra: Lower clocksource rating for some Tegra's (87bd4c26) · Commits · 戴 / test

drivers/clocksource/timer-tegra20.c

+26 −4

Original line number	Diff line number	Diff line
		@@ -109,7 +109,6 @@ static DEFINE_PER_CPU(struct timer_of, tegra_to) = {

		.clkevt = {
		.name = "tegra_timer",
		.rating = 460,
		.features = CLOCK_EVT_FEAT_ONESHOT \| CLOCK_EVT_FEAT_PERIODIC,
		.set_next_event = tegra_timer_set_next_event,
		.set_state_shutdown = tegra_timer_shutdown,
		@@ -219,7 +218,8 @@ static inline unsigned int tegra_irq_idx_for_cpu(int cpu, bool tegra20)
		return TIMER10_IRQ_IDX + cpu;
		}

		static int __init tegra_init_timer(struct device_node *np, bool tegra20)
		static int __init tegra_init_timer(struct device_node *np, bool tegra20,
		int rating)
		{
		struct timer_of *to;
		int cpu, ret;
		@@ -282,6 +282,7 @@ static int __init tegra_init_timer(struct device_node *np, bool tegra20)

		cpu_to = per_cpu_ptr(&tegra_to, cpu);
		cpu_to->of_base.base = timer_reg_base + base;
		cpu_to->clkevt.rating = rating;
		cpu_to->clkevt.cpumask = cpumask_of(cpu);
		cpu_to->clkevt.irq = irq_of_parse_and_map(np, idx);
		if (!cpu_to->clkevt.irq) {
		@@ -341,13 +342,34 @@ out:

		static int __init tegra210_init_timer(struct device_node *np)
		{
		return tegra_init_timer(np, false);
		/*
		* Arch-timer can't survive across power cycle of CPU core and
		* after CPUPORESET signal due to a system design shortcoming,
		* hence tegra-timer is more preferable on Tegra210.
		*/
		return tegra_init_timer(np, false, 460);
		}
		TIMER_OF_DECLARE(tegra210_timer, "nvidia,tegra210-timer", tegra210_init_timer);

		static int __init tegra20_init_timer(struct device_node *np)
		{
		return tegra_init_timer(np, true);
		int rating;

		/*
		* Tegra20 and Tegra30 have Cortex A9 CPU that has a TWD timer,
		* that timer runs off the CPU clock and hence is subjected to
		* a jitter caused by DVFS clock rate changes. Tegra-timer is
		* more preferable for older Tegra's, while later SoC generations
		* have arch-timer as a main per-CPU timer and it is not affected
		* by DVFS changes.
		*/
		if (of_machine_is_compatible("nvidia,tegra20") \|\|
		of_machine_is_compatible("nvidia,tegra30"))
		rating = 460;
		else
		rating = 330;

		return tegra_init_timer(np, true, rating);
		}
		TIMER_OF_DECLARE(tegra20_timer, "nvidia,tegra20-timer", tegra20_init_timer);

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