Patch "Bluetooth: hci_bcm: Validate IRQ before using it" has been added to the 4.15-stable tree

This is a note to let you know that I've just added the patch titled

Bluetooth: hci_bcm: Validate IRQ before using it

to the 4.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
bluetooth-hci_bcm-validate-irq-before-using-it.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: "Ronald Tschal�r" <[email protected]>
Date: Wed, 10 Jan 2018 16:32:10 +0100
Subject: Bluetooth: hci_bcm: Validate IRQ before using it

From: "Ronald Tschal�r" <[email protected]>

[ Upstream commit 4a59f1fab91e9445e34c69d8e4401a0d6bdbe914 ]

The ->close, ->suspend and ->resume hooks assume presence of a valid IRQ if the device is wakeup capable. However it's entirely possible that wakeup was enabled by some other entity besides this driver and in this case the user will get a WARN splat if no valid IRQ was found. Avoid by checking if the IRQ is valid, i.e. > 0.

Case in point: On recent MacBook Pros, the Bluetooth device lacks an IRQ (because host wakeup is handled by the SMC, independently of the operating system), but it does possess a _PRW method (which specifies the SMC's GPE as wake event). The ACPI core therefore automatically marks the physical Bluetooth device wakeup capable upon binding it to its ACPI companion:

device_set_wakeup_capable+0x96/0xb0
acpi_bind_one+0x28a/0x310
acpi_platform_notify+0x20/0xa0
device_add+0x215/0x690
serdev_device_add+0x57/0xf0
acpi_serdev_add_device+0xc9/0x110
acpi_ns_walk_namespace+0x131/0x280
acpi_walk_namespace+0xf5/0x13d
serdev_controller_add+0x6f/0x110
serdev_tty_port_register+0x98/0xf0
tty_port_register_device_attr_serdev+0x3a/0x70
uart_add_one_port+0x268/0x500
serial8250_register_8250_port+0x32e/0x490
dw8250_probe+0x46c/0x720
platform_drv_probe+0x35/0x90
driver_probe_device+0x300/0x450
bus_for_each_drv+0x67/0xb0
__device_attach+0xde/0x160
bus_probe_device+0x9c/0xb0
device_add+0x448/0x690
platform_device_add+0x10e/0x260
mfd_add_device+0x392/0x4c0
mfd_add_devices+0xb1/0x110
intel_lpss_probe+0x2a9/0x610 [intel_lpss]
intel_lpss_pci_probe+0x7a/0xa8 [intel_lpss_pci]

---
 drivers/bluetooth/hci_bcm.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

@@ -379,7 +379,7 @@ static int bcm_close(struct hci_uart *hu
 		pm_runtime_disable(bdev->dev);
 		pm_runtime_set_suspended(bdev->dev);
 
-		if (device_can_wakeup(bdev->dev)) {
+		if (bdev->irq > 0) {
 			devm_free_irq(bdev->dev, bdev->irq, bdev);
 			device_init_wakeup(bdev->dev, false);
 		}

@@ -628,7 +628,7 @@ static int bcm_suspend(struct device *de
 	if (pm_runtime_active(dev))
 		bcm_suspend_device(dev);
 
-	if (device_may_wakeup(dev)) {
+	if (device_may_wakeup(dev) && bdev->irq > 0) {
 		error = enable_irq_wake(bdev->irq);
 		if (!error)
 			bt_dev_dbg(bdev, "BCM irq: enabled");

@@ -658,7 +658,7 @@ static int bcm_resume(struct device *dev
 	if (!bdev->hu)
 		goto unlock;
 
-	if (device_may_wakeup(dev)) {
+	if (device_may_wakeup(dev) && bdev->irq > 0) {
 		disable_irq_wake(bdev->irq);
 		bt_dev_dbg(bdev, "BCM irq: disabled");
 	}

Patches currently in stable-queue which might be from [email protected] are

queue-4.15/bluetooth-hci_bcm-validate-irq-before-using-it.patch