6.6-stable review patch. If anyone has any objections, please let me know.
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From: Doug Berger opendmb@gmail.com
[ Upstream commit e005a9b35b464be5b2e0194f717e90e7e496785d ]
Some devices (e.g. BCM72112) use an alarm_irq interrupt that is connected to a level interrupt controller rather than an edge interrupt controller. In this case, the interrupt cannot be left enabled by the irq handler while preserving the hardware wake-up signal on wake capable devices or an interrupt storm will occur.
The alarm_expired flag is introduced to allow the disabling of the interrupt when an alarm expires and to support balancing the calls to disable_irq() and enable_irq() in accordance with the existing design.
Fixes: 24304a87158a ("rtc: brcmstb-waketimer: allow use as non-wake alarm") Signed-off-by: Doug Berger opendmb@gmail.com Reviewed-by: Florian Fainelli florian.fainelli@broadcom.com Link: https://lore.kernel.org/r/20230830224747.1663044-1-opendmb@gmail.com Signed-off-by: Alexandre Belloni alexandre.belloni@bootlin.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/rtc/rtc-brcmstb-waketimer.c | 47 ++++++++++++++++++++++++++--- 1 file changed, 42 insertions(+), 5 deletions(-)
diff --git a/drivers/rtc/rtc-brcmstb-waketimer.c b/drivers/rtc/rtc-brcmstb-waketimer.c index 3cdc015692ca6..1a65a4e0dc003 100644 --- a/drivers/rtc/rtc-brcmstb-waketimer.c +++ b/drivers/rtc/rtc-brcmstb-waketimer.c @@ -1,6 +1,6 @@ // SPDX-License-Identifier: GPL-2.0-only /* - * Copyright © 2014-2017 Broadcom + * Copyright © 2014-2023 Broadcom */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt @@ -34,6 +34,7 @@ struct brcmstb_waketmr { u32 rate; unsigned long rtc_alarm; bool alarm_en; + bool alarm_expired; };
#define BRCMSTB_WKTMR_EVENT 0x00 @@ -64,6 +65,11 @@ static inline void brcmstb_waketmr_clear_alarm(struct brcmstb_waketmr *timer) writel_relaxed(reg - 1, timer->base + BRCMSTB_WKTMR_ALARM); writel_relaxed(WKTMR_ALARM_EVENT, timer->base + BRCMSTB_WKTMR_EVENT); (void)readl_relaxed(timer->base + BRCMSTB_WKTMR_EVENT); + if (timer->alarm_expired) { + timer->alarm_expired = false; + /* maintain call balance */ + enable_irq(timer->alarm_irq); + } }
static void brcmstb_waketmr_set_alarm(struct brcmstb_waketmr *timer, @@ -105,10 +111,17 @@ static irqreturn_t brcmstb_alarm_irq(int irq, void *data) return IRQ_HANDLED;
if (timer->alarm_en) { - if (!device_may_wakeup(timer->dev)) + if (device_may_wakeup(timer->dev)) { + disable_irq_nosync(irq); + timer->alarm_expired = true; + } else { writel_relaxed(WKTMR_ALARM_EVENT, timer->base + BRCMSTB_WKTMR_EVENT); + } rtc_update_irq(timer->rtc, 1, RTC_IRQF | RTC_AF); + } else { + writel_relaxed(WKTMR_ALARM_EVENT, + timer->base + BRCMSTB_WKTMR_EVENT); }
return IRQ_HANDLED; @@ -221,8 +234,14 @@ static int brcmstb_waketmr_alarm_enable(struct device *dev, !brcmstb_waketmr_is_pending(timer)) return -EINVAL; timer->alarm_en = true; - if (timer->alarm_irq) + if (timer->alarm_irq) { + if (timer->alarm_expired) { + timer->alarm_expired = false; + /* maintain call balance */ + enable_irq(timer->alarm_irq); + } enable_irq(timer->alarm_irq); + } } else if (!enabled && timer->alarm_en) { if (timer->alarm_irq) disable_irq(timer->alarm_irq); @@ -352,6 +371,17 @@ static int brcmstb_waketmr_suspend(struct device *dev) return brcmstb_waketmr_prepare_suspend(timer); }
+static int brcmstb_waketmr_suspend_noirq(struct device *dev) +{ + struct brcmstb_waketmr *timer = dev_get_drvdata(dev); + + /* Catch any alarms occurring prior to noirq */ + if (timer->alarm_expired && device_may_wakeup(dev)) + return -EBUSY; + + return 0; +} + static int brcmstb_waketmr_resume(struct device *dev) { struct brcmstb_waketmr *timer = dev_get_drvdata(dev); @@ -368,10 +398,17 @@ static int brcmstb_waketmr_resume(struct device *dev)
return ret; } +#else +#define brcmstb_waketmr_suspend NULL +#define brcmstb_waketmr_suspend_noirq NULL +#define brcmstb_waketmr_resume NULL #endif /* CONFIG_PM_SLEEP */
-static SIMPLE_DEV_PM_OPS(brcmstb_waketmr_pm_ops, - brcmstb_waketmr_suspend, brcmstb_waketmr_resume); +static const struct dev_pm_ops brcmstb_waketmr_pm_ops = { + .suspend = brcmstb_waketmr_suspend, + .suspend_noirq = brcmstb_waketmr_suspend_noirq, + .resume = brcmstb_waketmr_resume, +};
static const __maybe_unused struct of_device_id brcmstb_waketmr_of_match[] = { { .compatible = "brcm,brcmstb-waketimer" },