USB: chipidea: fix interrupt deadlock

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>

diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c
index 2b18f50..a56f063 100644 (file)
--- a/drivers/usb/chipidea/core.c
+++ b/drivers/usb/chipidea/core.c
@@ -514,7 +514,7 @@ 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;
@@ -567,6 +567,15 @@ static irqreturn_t ci_irq(int irq, void *data)
        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)
 {
@@ -576,7 +585,7 @@ static int ci_cable_notifier(struct notifier_block *nb, unsigned long event,
        cbl->connected = event;
        cbl->changed = true;
 
-       ci_irq(ci->irq, ci);
+       ci_irq(ci);
        return NOTIFY_DONE;
 }
 
@@ -617,7 +626,7 @@ static int ci_usb_role_switch_set(struct usb_role_switch *sw,
        if (cable) {
                cable->changed = true;
                cable->connected = false;
-               ci_irq(ci->irq, ci);
+               ci_irq(ci);
                spin_unlock_irqrestore(&ci->lock, flags);
                if (ci->wq && role != USB_ROLE_NONE)
                        flush_workqueue(ci->wq);
@@ -635,7 +644,7 @@ static int ci_usb_role_switch_set(struct usb_role_switch *sw,
        if (cable) {
                cable->changed = true;
                cable->connected = true;
-               ci_irq(ci->irq, ci);
+               ci_irq(ci);
        }
        spin_unlock_irqrestore(&ci->lock, flags);
        pm_runtime_put_sync(ci->dev);
@@ -1174,7 +1183,7 @@ static int ci_hdrc_probe(struct platform_device *pdev)
                }
        }
 
-       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;
@@ -1295,11 +1304,11 @@ static void ci_extcon_wakeup_int(struct ci_hdrc *ci)
 
        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)