From 9aaa81c3366e8393a62374e3a1c67c69edc07b8a Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan@kernel.org>
Date: Thu, 21 Oct 2021 10:34:47 +0200
Subject: [PATCH] USB: chipidea: fix interrupt deadlock
Git-commit: 9aaa81c3366e8393a62374e3a1c67c69edc07b8a
References: git-fixes
Patch-mainline: v5.16-rc1

Chipidea core was calling the interrupt handler from non-IRQ context
with interrupts enabled, something which can lead to a deadlock if
there's an actual interrupt trying to take a lock that's already held
(e.g. the controller lock in udc_irq()).

Add a wrapper that can be used to fake interrupts instead of calling the
handler directly.

Fixes: 3ecb3e09b042 ("usb: chipidea: Use extcon framework for VBUS and ID detect")
Fixes: 876d4e1e8298 ("usb: chipidea: core: add wakeup support for extcon")
Cc: Peter Chen <peter.chen@kernel.org>
Cc: stable@vger.kernel.org      # 4.4
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20211021083447.20078-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/usb/chipidea/core.c |   19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

--- a/drivers/usb/chipidea/core.c
+++ b/drivers/usb/chipidea/core.c
@@ -535,7 +535,7 @@ int hw_device_reset(struct ci_hdrc *ci)
 	return 0;
 }
 
-static irqreturn_t ci_irq(int irq, void *data)
+static irqreturn_t ci_irq_handler(int irq, void *data)
 {
 	struct ci_hdrc *ci = data;
 	irqreturn_t ret = IRQ_NONE;
@@ -588,6 +588,15 @@ static irqreturn_t ci_irq(int irq, void
 	return ret;
 }
 
+static void ci_irq(struct ci_hdrc *ci)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	ci_irq_handler(ci->irq, ci);
+	local_irq_restore(flags);
+}
+
 static int ci_cable_notifier(struct notifier_block *nb, unsigned long event,
 			     void *ptr)
 {
@@ -597,7 +606,7 @@ static int ci_cable_notifier(struct noti
 	cbl->connected = event;
 	cbl->changed = true;
 
-	ci_irq(ci->irq, ci);
+	ci_irq(ci);
 	return NOTIFY_DONE;
 }
 
@@ -1043,7 +1052,7 @@ static int ci_hdrc_probe(struct platform
 		}
 	}
 
-	ret = devm_request_irq(dev, ci->irq, ci_irq, IRQF_SHARED,
+	ret = devm_request_irq(dev, ci->irq, ci_irq_handler, IRQF_SHARED,
 			ci->platdata->name, ci);
 	if (ret)
 		goto stop;
@@ -1162,11 +1171,11 @@ static void ci_extcon_wakeup_int(struct
 
 	if (!IS_ERR(cable_id->edev) && ci->is_otg &&
 		(otgsc & OTGSC_IDIE) && (otgsc & OTGSC_IDIS))
-		ci_irq(ci->irq, ci);
+		ci_irq(ci);
 
 	if (!IS_ERR(cable_vbus->edev) && ci->is_otg &&
 		(otgsc & OTGSC_BSVIE) && (otgsc & OTGSC_BSVIS))
-		ci_irq(ci->irq, ci);
+		ci_irq(ci);
 }
 
 static int ci_controller_resume(struct device *dev)