From: Tony Lindgren <tony@atomide.com> To: Daniel Lezcano <daniel.lezcano@linaro.org>, Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH] clocksource/drivers/timer-ti-dm: Do reset before enable Date: Mon, 17 Aug 2020 12:24:28 +0300 [thread overview] Message-ID: <20200817092428.6176-1-tony@atomide.com> (raw) 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> --- drivers/clocksource/timer-ti-dm-systimer.c | 44 +++++++++++----------- 1 file changed, 23 insertions(+), 21 deletions(-) diff --git a/drivers/clocksource/timer-ti-dm-systimer.c b/drivers/clocksource/timer-ti-dm-systimer.c --- 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(struct dmtimer_systimer *t) 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_reset(struct dmtimer_systimer *t) 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_clock(struct dmtimer_systimer *t, 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(struct device_node *np, 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)); -- 2.28.0
WARNING: multiple messages have this Message-ID (diff)
From: Tony Lindgren <tony@atomide.com> To: Daniel Lezcano <daniel.lezcano@linaro.org>, Thomas Gleixner <tglx@linutronix.de> Cc: linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH] clocksource/drivers/timer-ti-dm: Do reset before enable Date: Mon, 17 Aug 2020 12:24:28 +0300 [thread overview] Message-ID: <20200817092428.6176-1-tony@atomide.com> (raw) 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> --- drivers/clocksource/timer-ti-dm-systimer.c | 44 +++++++++++----------- 1 file changed, 23 insertions(+), 21 deletions(-) diff --git a/drivers/clocksource/timer-ti-dm-systimer.c b/drivers/clocksource/timer-ti-dm-systimer.c --- 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(struct dmtimer_systimer *t) 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_reset(struct dmtimer_systimer *t) 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_clock(struct dmtimer_systimer *t, 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(struct device_node *np, 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)); -- 2.28.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next reply other threads:[~2020-08-17 9:24 UTC|newest] Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-08-17 9:24 Tony Lindgren [this message] 2020-08-17 9:24 ` [PATCH] clocksource/drivers/timer-ti-dm: Do reset before enable Tony Lindgren 2020-08-24 11:00 ` Daniel Lezcano 2020-08-24 11:00 ` Daniel Lezcano 2020-09-27 9:27 ` [tip: timers/urgent] " tip-bot2 for Tony Lindgren
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