From: Tony Lindgren tony@atomide.com
commit 164805157f3c6834670afbaff563353c773131f1 upstream.
Commit 6cfcd5563b4f ("clocksource/drivers/timer-ti-dm: Fix suspend and resume for am3 and am4") exposed a new issue for type2 dual mode timers on at least omap5 where the clockevent will stop when the SoC starts entering idle states during the boot.
Turns out we are wrongly first enabling the system timer and then resetting it, while we must also re-enable it after reset. The current sequence leaves the timer module in a partially initialized state. This issue went unnoticed earlier with ti-sysc driver reconfiguring the timer module until we fixed the issue of ti-sysc reconfiguring system timers.
Let's fix the issue by calling dmtimer_systimer_enable() from reset for both type1 and type2 timers, and switch the order of reset and enable in dmtimer_systimer_setup(). Let's also move dmtimer_systimer_enable() and dmtimer_systimer_disable() to do this without adding forward declarations.
Fixes: 6cfcd5563b4f ("clocksource/drivers/timer-ti-dm: Fix suspend and resume for am3 and am4") Reported-by: H. Nikolaus Schaller hns@goldelico.com Signed-off-by: Tony Lindgren tony@atomide.com Signed-off-by: Daniel Lezcano daniel.lezcano@linaro.org Link: https://lore.kernel.org/r/20200817092428.6176-1-tony@atomide.com Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/clocksource/timer-ti-dm-systimer.c | 44 +++++++++++++++-------------- 1 file changed, 23 insertions(+), 21 deletions(-)
--- a/drivers/clocksource/timer-ti-dm-systimer.c +++ b/drivers/clocksource/timer-ti-dm-systimer.c @@ -69,12 +69,33 @@ static bool dmtimer_systimer_revision1(s return !(tidr >> 16); }
+static void dmtimer_systimer_enable(struct dmtimer_systimer *t) +{ + u32 val; + + if (dmtimer_systimer_revision1(t)) + val = DMTIMER_TYPE1_ENABLE; + else + val = DMTIMER_TYPE2_ENABLE; + + writel_relaxed(val, t->base + t->sysc); +} + +static void dmtimer_systimer_disable(struct dmtimer_systimer *t) +{ + if (!dmtimer_systimer_revision1(t)) + return; + + writel_relaxed(DMTIMER_TYPE1_DISABLE, t->base + t->sysc); +} + static int __init dmtimer_systimer_type1_reset(struct dmtimer_systimer *t) { void __iomem *syss = t->base + OMAP_TIMER_V1_SYS_STAT_OFFSET; int ret; u32 l;
+ dmtimer_systimer_enable(t); writel_relaxed(BIT(1) | BIT(2), t->base + t->ifctrl); ret = readl_poll_timeout_atomic(syss, l, l & BIT(0), 100, DMTIMER_RESET_WAIT); @@ -88,6 +109,7 @@ static int __init dmtimer_systimer_type2 void __iomem *sysc = t->base + t->sysc; u32 l;
+ dmtimer_systimer_enable(t); l = readl_relaxed(sysc); l |= BIT(0); writel_relaxed(l, sysc); @@ -336,26 +358,6 @@ static int __init dmtimer_systimer_init_ return 0; }
-static void dmtimer_systimer_enable(struct dmtimer_systimer *t) -{ - u32 val; - - if (dmtimer_systimer_revision1(t)) - val = DMTIMER_TYPE1_ENABLE; - else - val = DMTIMER_TYPE2_ENABLE; - - writel_relaxed(val, t->base + t->sysc); -} - -static void dmtimer_systimer_disable(struct dmtimer_systimer *t) -{ - if (!dmtimer_systimer_revision1(t)) - return; - - writel_relaxed(DMTIMER_TYPE1_DISABLE, t->base + t->sysc); -} - static int __init dmtimer_systimer_setup(struct device_node *np, struct dmtimer_systimer *t) { @@ -409,8 +411,8 @@ static int __init dmtimer_systimer_setup t->wakeup = regbase + _OMAP_TIMER_WAKEUP_EN_OFFSET; t->ifctrl = regbase + _OMAP_TIMER_IF_CTRL_OFFSET;
- dmtimer_systimer_enable(t); dmtimer_systimer_reset(t); + dmtimer_systimer_enable(t); pr_debug("dmtimer rev %08x sysc %08x\n", readl_relaxed(t->base), readl_relaxed(t->base + t->sysc));