From 01a6e108101fcc5c5da6886d28d01ea43badef92 Mon Sep 17 00:00:00 2001
From: Caleb Connolly <caleb.connolly@linaro.org>
Date: Sun, 15 Jan 2023 17:59:24 +0000
Subject: [PATCH] net: ipa: disable ipa interrupt during suspend
[ Upstream commit 9ec9b2a30853ba843b70ea16f196e5fe3327be5f ]
The IPA interrupt can fire when pm_runtime is disabled due to it racing
with the PM suspend/resume code. This causes a splat in the interrupt
handler when it tries to call pm_runtime_get().
Explicitly disable the interrupt in our ->suspend callback, and
re-enable it in ->resume to avoid this. If there is an interrupt pending
it will be handled after resuming. The interrupt is a wake_irq, as a
result even when disabled if it fires it will cause the system to wake
from suspend as well as cancel any suspend transition that may be in
progress. If there is an interrupt pending, the ipa_isr_thread handler
will be called after resuming.
Fixes: 1aac309d3207 ("net: ipa: use autosuspend")
Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>
Reviewed-by: Alex Elder <elder@linaro.org>
Link: https://lore.kernel.org/r/20230115175925.465918-1-caleb.connolly@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ipa/ipa_interrupt.c | 10 ++++++++++
drivers/net/ipa/ipa_interrupt.h | 16 ++++++++++++++++
drivers/net/ipa/ipa_power.c | 17 +++++++++++++++++
3 files changed, 43 insertions(+)
diff --git a/drivers/net/ipa/ipa_interrupt.c b/drivers/net/ipa/ipa_interrupt.c
index b35170a93b0fa..0c9ff8c055a05 100644
--- a/drivers/net/ipa/ipa_interrupt.c
+++ b/drivers/net/ipa/ipa_interrupt.c
@@ -122,6 +122,16 @@ out_power_put:
return IRQ_HANDLED;
}
+void ipa_interrupt_irq_disable(struct ipa *ipa)
+{
+ disable_irq(ipa->interrupt->irq);
+}
+
+void ipa_interrupt_irq_enable(struct ipa *ipa)
+{
+ enable_irq(ipa->interrupt->irq);
+}
+
/* Common function used to enable/disable TX_SUSPEND for an endpoint */
static void ipa_interrupt_suspend_control(struct ipa_interrupt *interrupt,
u32 endpoint_id, bool enable)
diff --git a/drivers/net/ipa/ipa_interrupt.h b/drivers/net/ipa/ipa_interrupt.h
index 231390cea52a2..16aa84ee0094f 100644
--- a/drivers/net/ipa/ipa_interrupt.h
+++ b/drivers/net/ipa/ipa_interrupt.h
@@ -85,6 +85,22 @@ void ipa_interrupt_suspend_clear_all(struct ipa_interrupt *interrupt);
*/
void ipa_interrupt_simulate_suspend(struct ipa_interrupt *interrupt);
+/**
+ * ipa_interrupt_irq_enable() - Enable IPA interrupts
+ * @ipa: IPA pointer
+ *
+ * This enables the IPA interrupt line
+ */
+void ipa_interrupt_irq_enable(struct ipa *ipa);
+
+/**
+ * ipa_interrupt_irq_disable() - Disable IPA interrupts
+ * @ipa: IPA pointer
+ *
+ * This disables the IPA interrupt line
+ */
+void ipa_interrupt_irq_disable(struct ipa *ipa);
+
/**
* ipa_interrupt_config() - Configure the IPA interrupt framework
* @ipa: IPA pointer
diff --git a/drivers/net/ipa/ipa_power.c b/drivers/net/ipa/ipa_power.c
index f2989aac47a62..07fb367cfc99d 100644
--- a/drivers/net/ipa/ipa_power.c
+++ b/drivers/net/ipa/ipa_power.c
@@ -277,6 +277,17 @@ static int ipa_suspend(struct device *dev)
__set_bit(IPA_POWER_FLAG_SYSTEM, ipa->power->flags);
+ /* Increment the disable depth to ensure that the IRQ won't
+ * be re-enabled until the matching _enable call in
+ * ipa_resume(). We do this to ensure that the interrupt
+ * handler won't run whilst PM runtime is disabled.
+ *
+ * Note that disabling the IRQ is NOT the same as disabling
+ * irq wake. If wakeup is enabled for the IPA then the IRQ
+ * will still cause the system to wake up, see irq_set_irq_wake().
+ */
+ ipa_interrupt_irq_disable(ipa);
+
return pm_runtime_force_suspend(dev);
}
@@ -289,6 +300,12 @@ static int ipa_resume(struct device *dev)
__clear_bit(IPA_POWER_FLAG_SYSTEM, ipa->power->flags);
+ /* Now that PM runtime is enabled again it's safe
+ * to turn the IRQ back on and process any data
+ * that was received during suspend.
+ */
+ ipa_interrupt_irq_enable(ipa);
+
return ret;
}
--
2.30.2