On Thu, Feb 21, 2019 at 04:30:51PM -0800, Brian Norris wrote:
> Badly-designed systems might have (for example) active-high wake pins
> that default to high (e.g., because of external pull ups) until they
> have an active firmware which starts driving it low. This can cause an
> interrupt storm in the time between request_irq() and disable_irq().
>
> We don't support shared interrupts here, so let's just pre-configure the
> interrupt to avoid auto-enabling it.
>
> Fixes: fd913ef7ce61 ("Bluetooth: btusb: Add out-of-band wakeup support")
> Signed-off-by: Brian Norris <briannorris@xxxxxxxxxxxx>
> ---
> drivers/bluetooth/btusb.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
> index 4761499db9ee..470ee68555d9 100644
> --- a/drivers/bluetooth/btusb.c
> +++ b/drivers/bluetooth/btusb.c
> @@ -2885,6 +2885,7 @@ static int btusb_config_oob_wake(struct hci_dev *hdev)
> return 0;
> }
>
> + irq_set_status_flags(irq, IRQ_NOAUTOEN);
> ret = devm_request_irq(&hdev->dev, irq, btusb_oob_wake_handler,
> 0, "OOB Wake-on-BT", data);
> if (ret) {
> @@ -2899,7 +2900,6 @@ static int btusb_config_oob_wake(struct hci_dev *hdev)
> }
>
> data->oob_wake_irq = irq;
> - disable_irq(irq);
> bt_dev_info(hdev, "OOB Wake-on-BT configured at IRQ %u", irq);
> return 0;
> }
Reviewed-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
