linux-kernel - [PATCH v3 3/3] pmdomain: ti_sci: handle wake IRQs for IO daisy chain wakeups

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Message-Id: <20240905-lpm-v6-10-constraints-pmdomain-v3-3-e359cbb39654@baylibre.com>
Date: Thu, 05 Sep 2024 15:02:51 -0700
From: Kevin Hilman <khilman@...libre.com>
To: Ulf Hansson <ulf.hansson@...aro.org>, linux-pm@...r.kernel.org
Cc: Nishanth Menon <nm@...com>, Vibhore Vardhan <vibhore@...com>, 
 Dhruva Gole <d-gole@...com>, Akashdeep Kaur <a-kaur@...com>, 
 Sebin Francis <sebin.francis@...com>, 
 Markus Schneider-Pargmann <msp@...libre.com>, 
 linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: [PATCH v3 3/3] pmdomain: ti_sci: handle wake IRQs for IO daisy
 chain wakeups

When a device supports IO daisy-chain wakeups, it uses a dedicated
wake IRQ.  Devices with IO daisy-chain wakeups enabled should not set
wakeup constraints since these can happen even from deep power states,
so should not prevent the DM from picking deep power states.

Wake IRQs are set with dev_pm_set_wake_irq() or
dev_pm_set_dedicated_wake_irq().  The latter is used by the serial
driver used on K3 platforms (drivers/tty/serial/8250/8250_omap.c)
when the interrupts-extended property is used to describe the
dedicated wakeup interrupt.

Detect these wake IRQs in the suspend path, and if set, skip sending
constraint.

Signed-off-by: Kevin Hilman <khilman@...libre.com>
---
 drivers/pmdomain/ti/ti_sci_pm_domains.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/pmdomain/ti/ti_sci_pm_domains.c b/drivers/pmdomain/ti/ti_sci_pm_domains.c
index 1ab1e46924ab..747a7a33c0a9 100644
--- a/drivers/pmdomain/ti/ti_sci_pm_domains.c
+++ b/drivers/pmdomain/ti/ti_sci_pm_domains.c
@@ -82,6 +82,13 @@ static inline void ti_sci_pd_set_wkup_constraint(struct device *dev)
 	int ret;
 
 	if (device_may_wakeup(dev)) {
+		/*
+		 * If device can wakeup using IO daisy chain wakeups,
+		 * we do not want to set a constraint.
+		 */
+		if (dev->power.wakeirq)
+			dev_dbg(dev, "%s: has wake IRQ, not setting constraints\n", __func__);
+
 		ret = ti_sci->ops.pm_ops.set_device_constraint(ti_sci, pd->idx,
 							       TISCI_MSG_CONSTRAINT_SET);
 		if (!ret)

-- 
2.46.0