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SubjectRe: [RESEND] clocksource: sun4i: Fix the bug that tick_resume stucks
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On 2022/10/9 11:25, Victor Hassan wrote:
> Currently syscore_resume() will stuck on tick_resume().
> Fix this by changing `.tick_resume` from
> sun4i_clkevt_shutdown() to a new function sun4i_tick_resume().
>
> Signed-off-by: Victor Hassan <victor@allwinnertech.com>
> ---
> drivers/clocksource/timer-sun4i.c | 131 ++++++++++++++++++++++--------
> 1 file changed, 96 insertions(+), 35 deletions(-)
>
> diff --git a/drivers/clocksource/timer-sun4i.c b/drivers/clocksource/timer-sun4i.c
> index 94dc6e42e983..574398c35a22 100644
> --- a/drivers/clocksource/timer-sun4i.c
> +++ b/drivers/clocksource/timer-sun4i.c
> @@ -38,6 +38,19 @@
>
> #define TIMER_SYNC_TICKS 3
>
> +/* Registers which needs to be saved and restored before and after sleeping */
> +static u32 sun4i_timer_regs_offset[] = {
> + TIMER_IRQ_EN_REG,
> + TIMER_CTL_REG(0),
> + TIMER_INTVAL_REG(0),
> + TIMER_CNTVAL_REG(0),
> + TIMER_CTL_REG(1),
> + TIMER_INTVAL_REG(1),
> + TIMER_CNTVAL_REG(1),
> +};
> +
> +static void __iomem *sun4i_timer_sched_base __read_mostly;
> +
> /*
> * When we disable a timer, we need to wait at least for 2 cycles of
> * the timer source clock. We will use for that the clocksource timer
> @@ -79,10 +92,41 @@ static void sun4i_clkevt_time_start(void __iomem *base, u8 timer,
> base + TIMER_CTL_REG(timer));
> }
>
> +static inline void sun4i_timer_save_regs(struct timer_of *to)
> +{
> + void __iomem *base = timer_of_base(to);
> + int i;
> + u32 *regs_backup = (u32 *)to->private_data;
> +
> + for (i = 0; i < ARRAY_SIZE(sun4i_timer_regs_offset); i++)
> + regs_backup[i] = readl(base + sun4i_timer_regs_offset[i]);
> +}
> +
> +static inline void sun4i_timer_restore_regs(struct timer_of *to)
> +{
> + void __iomem *base = timer_of_base(to);
> + int i;
> + u32 *regs_backup = (u32 *)to->private_data;
> +
> + for (i = 0; i < ARRAY_SIZE(sun4i_timer_regs_offset); i++)
> + writel(regs_backup[i], base + sun4i_timer_regs_offset[i]);
> +}
> +
> static int sun4i_clkevt_shutdown(struct clock_event_device *evt)
> {
> struct timer_of *to = to_timer_of(evt);
>
> + sun4i_timer_save_regs(to);
> + sun4i_clkevt_time_stop(timer_of_base(to), 0);
> +
> + return 0;
> +}
> +
> +static int sun4i_tick_resume(struct clock_event_device *evt)
> +{
> + struct timer_of *to = to_timer_of(evt);
> +
> + sun4i_timer_restore_regs(to);
> sun4i_clkevt_time_stop(timer_of_base(to), 0);
>
> return 0;
> @@ -137,45 +181,54 @@ static irqreturn_t sun4i_timer_interrupt(int irq, void *dev_id)
> return IRQ_HANDLED;
> }
>
> -static struct timer_of to = {
> - .flags = TIMER_OF_IRQ | TIMER_OF_CLOCK | TIMER_OF_BASE,
> -
> - .clkevt = {
> - .name = "sun4i_tick",
> - .rating = 350,
> - .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
> - .set_state_shutdown = sun4i_clkevt_shutdown,
> - .set_state_periodic = sun4i_clkevt_set_periodic,
> - .set_state_oneshot = sun4i_clkevt_set_oneshot,
> - .tick_resume = sun4i_clkevt_shutdown,
> - .set_next_event = sun4i_clkevt_next_event,
> - .cpumask = cpu_possible_mask,
> - },
> -
> - .of_irq = {
> - .handler = sun4i_timer_interrupt,
> - .flags = IRQF_TIMER | IRQF_IRQPOLL,
> - },
> -};
> +static void __init sun4i_clockevent_init(struct timer_of *to)
> +{
> + to->clkevt.name = "sun4i_tick";
> + to->clkevt.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
> + to->clkevt.set_state_shutdown = sun4i_clkevt_shutdown;
> + to->clkevt.set_state_periodic = sun4i_clkevt_set_periodic;
> + to->clkevt.set_state_oneshot = sun4i_clkevt_set_oneshot;
> + to->clkevt.tick_resume = sun4i_tick_resume;
> + to->clkevt.set_next_event = sun4i_clkevt_next_event;
> + to->clkevt.cpumask = cpu_possible_mask;
> + to->of_irq.flags = IRQF_TIMER | IRQF_IRQPOLL;
> +
> + sun4i_timer_sched_base = timer_of_base(to) + TIMER_CNTVAL_REG(1);
> +}
>
> static u64 notrace sun4i_timer_sched_read(void)
> {
> - return ~readl(timer_of_base(&to) + TIMER_CNTVAL_REG(1));
> + return (u64)~readl(sun4i_timer_sched_base);
> }
>
> static int __init sun4i_timer_init(struct device_node *node)
> {
> + struct timer_of *to;
> int ret;
> u32 val;
>
> - ret = timer_of_init(node, &to);
> + to = kzalloc(sizeof(*to), GFP_KERNEL);
> + if (!to)
> + return -ENOMEM;
> +
> + to->flags = TIMER_OF_IRQ | TIMER_OF_CLOCK | TIMER_OF_BASE;
> + to->of_irq.handler = sun4i_timer_interrupt;
> + ret = timer_of_init(node, to);
> if (ret)
> - return ret;
> + goto err;
>
> - writel(~0, timer_of_base(&to) + TIMER_INTVAL_REG(1));
> + sun4i_clockevent_init(to);
> +
> + to->private_data = kcalloc(ARRAY_SIZE(sun4i_timer_regs_offset), sizeof(u32), GFP_KERNEL);
> + if (!to->private_data) {
> + ret = -ENOMEM;
> + goto err1;
> + }
> +
> + writel(~0, timer_of_base(to) + TIMER_INTVAL_REG(1));
> writel(TIMER_CTL_ENABLE | TIMER_CTL_RELOAD |
> TIMER_CTL_CLK_SRC(TIMER_CTL_CLK_SRC_OSC24M),
> - timer_of_base(&to) + TIMER_CTL_REG(1));
> + timer_of_base(to) + TIMER_CTL_REG(1));
>
> /*
> * sched_clock_register does not have priorities, and on sun6i and
> @@ -186,32 +239,40 @@ static int __init sun4i_timer_init(struct device_node *node)
> of_machine_is_compatible("allwinner,sun5i-a10s") ||
> of_machine_is_compatible("allwinner,suniv-f1c100s"))
> sched_clock_register(sun4i_timer_sched_read, 32,
> - timer_of_rate(&to));
> + timer_of_rate(to));
>
> - ret = clocksource_mmio_init(timer_of_base(&to) + TIMER_CNTVAL_REG(1),
> - node->name, timer_of_rate(&to), 350, 32,
> + ret = clocksource_mmio_init(timer_of_base(to) + TIMER_CNTVAL_REG(1),
> + node->name, timer_of_rate(to), 350, 32,
> clocksource_mmio_readl_down);
> if (ret) {
> pr_err("Failed to register clocksource\n");
> - return ret;
> + goto err2;
> }
>
> writel(TIMER_CTL_CLK_SRC(TIMER_CTL_CLK_SRC_OSC24M),
> - timer_of_base(&to) + TIMER_CTL_REG(0));
> + timer_of_base(to) + TIMER_CTL_REG(0));
>
> /* Make sure timer is stopped before playing with interrupts */
> - sun4i_clkevt_time_stop(timer_of_base(&to), 0);
> + sun4i_clkevt_time_stop(timer_of_base(to), 0);
>
> /* clear timer0 interrupt */
> - sun4i_timer_clear_interrupt(timer_of_base(&to));
> + sun4i_timer_clear_interrupt(timer_of_base(to));
>
> - clockevents_config_and_register(&to.clkevt, timer_of_rate(&to),
> + clockevents_config_and_register(&to->clkevt, timer_of_rate(to),
> TIMER_SYNC_TICKS, 0xffffffff);
>
> /* Enable timer0 interrupt */
> - val = readl(timer_of_base(&to) + TIMER_IRQ_EN_REG);
> - writel(val | TIMER_IRQ_EN(0), timer_of_base(&to) + TIMER_IRQ_EN_REG);
> + val = readl(timer_of_base(to) + TIMER_IRQ_EN_REG);
> + writel(val | TIMER_IRQ_EN(0), timer_of_base(to) + TIMER_IRQ_EN_REG);
> +
> + return ret;
>
> +err2:
> + kfree(to->private_data);
> +err1:
> + timer_of_cleanup(to);
> +err:
> + kfree(to);
> return ret;
> }
> TIMER_OF_DECLARE(sun4i, "allwinner,sun4i-a10-timer",

Hi Maxime,
Sorry to disturb. Just want to say that I'm looking forward to your
advice on this patch. Thank you : )

Regards,
Victor

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