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authorTony Lindgren <tony@atomide.com>2020-08-17 11:24:28 +0200
committerDaniel Lezcano <daniel.lezcano@linaro.org>2020-08-24 13:01:39 +0200
commit164805157f3c6834670afbaff563353c773131f1 (patch)
tree7f2a5a5d657fe32afa94253426d7d1867e406e50 /drivers/clocksource
parentclocksource/drivers/h8300_timer8: Fix wrong return value in h8300_8timer_init() (diff)
downloadlinux-164805157f3c6834670afbaff563353c773131f1.tar.xz
linux-164805157f3c6834670afbaff563353c773131f1.zip
clocksource/drivers/timer-ti-dm: Do reset before enable
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
Diffstat (limited to 'drivers/clocksource')
-rw-r--r--drivers/clocksource/timer-ti-dm-systimer.c44
1 files changed, 23 insertions, 21 deletions
diff --git a/drivers/clocksource/timer-ti-dm-systimer.c b/drivers/clocksource/timer-ti-dm-systimer.c
index f6fd1c1cc527..33b3e8aa2cc5 100644
--- 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));