[PATCH RESEND 1/2] Bluetooth: qca: fix NULL-deref on non-serdev suspend

[Johan Hovold <johan+linaro@kernel.org>]

Qualcomm ROME controllers can be registered from the Bluetooth line
discipline and in this case the HCI UART serdev pointer is NULL.

Add the missing sanity check to prevent a NULL-pointer dereference when
wakeup() is called for a non-serdev controller during suspend.

Just return true for now to restore the original behaviour and address
the crash with pre-6.2 kernels, which do not have commit e9b3e5b8c657
("Bluetooth: hci_qca: only assign wakeup with serial port support") that
causes the crash to happen already at setup() time.

Fixes: c1a74160eaf1 ("Bluetooth: hci_qca: Add device_may_wakeup support")
Cc: stable@vger.kernel.org      # 5.13
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/bluetooth/hci_qca.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
index 92fa20f5ac7d..94c85f4fbf3b 100644
--- a/drivers/bluetooth/hci_qca.c
+++ b/drivers/bluetooth/hci_qca.c
@@ -1672,6 +1672,9 @@ static bool qca_wakeup(struct hci_dev *hdev)
 	struct hci_uart *hu = hci_get_drvdata(hdev);
 	bool wakeup;
 
+	if (!hu->serdev)
+		return true;
+
 	/* BT SoC attached through the serial bus is handled by the serdev driver.
 	 * So we need to use the device handle of the serdev driver to get the
 	 * status of device may wakeup.
-- 
2.43.2