usb: typec: fusb302: Revert incorrect threaded irq fix

The fusb302 irq handler has been carefully optimized by Hans de Goede in
commit 207338e ("usb: typec: fusb302: Improve suspend/resume
handling"). A recent 'fix' undid most of that work to avoid a virtio-gpio
driver bug.

This reverts the incorrect fix, since it is of very low quality. It
reverts the quirks from Hans change (and thus reintroduces the problems
fixed by Hans) while keeping the overhead from the original change.

The proper fix to support using fusb302 with an interrupt line provided
by virtio-gpio must be implemented in the virtio driver instead, which
should support disabling the IRQ from the fusb302 interrupt routine.

Cc: Hans de Goede <[email protected]>
Cc: Yongbo Zhang <[email protected]>
Fixes: 1c2d81b ("usb: typec: fusb302: fix scheduling while atomic when using virtio-gpio")
Signed-off-by: Sebastian Reichel <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: sre

drivers/usb/typec/tcpm/fusb302.c

@@ -1485,6 +1485,9 @@ static irqreturn_t fusb302_irq_intn(int irq, void *dev_id)
 	struct fusb302_chip *chip = dev_id;
 	unsigned long flags;
 
+	/* Disable our level triggered IRQ until our irq_work has cleared it */
+	disable_irq_nosync(chip->gpio_int_n_irq);
+
 	spin_lock_irqsave(&chip->irq_lock, flags);
 	if (chip->irq_suspended)
 		chip->irq_while_suspended = true;
@@ -1627,6 +1630,7 @@ static void fusb302_irq_work(struct work_struct *work)
 	}
 done:
 	mutex_unlock(&chip->lock);
+	enable_irq(chip->gpio_int_n_irq);
 }
 
 static int init_gpio(struct fusb302_chip *chip)
@@ -1751,10 +1755,9 @@ static int fusb302_probe(struct i2c_client *client)
 		goto destroy_workqueue;
 	}
 
-	ret = devm_request_threaded_irq(dev, chip->gpio_int_n_irq,
-					NULL, fusb302_irq_intn,
-					IRQF_ONESHOT | IRQF_TRIGGER_LOW,
-					"fsc_interrupt_int_n", chip);
+	ret = request_irq(chip->gpio_int_n_irq, fusb302_irq_intn,
+			  IRQF_ONESHOT | IRQF_TRIGGER_LOW,
+			  "fsc_interrupt_int_n", chip);
 	if (ret < 0) {
 		dev_err(dev, "cannot request IRQ for GPIO Int_N, ret=%d", ret);
 		goto tcpm_unregister_port;
@@ -1779,6 +1782,7 @@ static void fusb302_remove(struct i2c_client *client)
 	struct fusb302_chip *chip = i2c_get_clientdata(client);
 
 	disable_irq_wake(chip->gpio_int_n_irq);
+	free_irq(chip->gpio_int_n_irq, chip);
 	cancel_work_sync(&chip->irq_work);
 	cancel_delayed_work_sync(&chip->bc_lvl_handler);
 	tcpm_unregister_port(chip->tcpm_port);