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* [PATCH] Bluetooth: btusb: request wake pin with NOAUTOEN
@ 2019-02-22  0:30 Brian Norris
  2019-02-22 18:35 ` Matthias Kaehlcke
  2019-03-26 18:48 ` Brian Norris
  0 siblings, 2 replies; 4+ messages in thread
From: Brian Norris @ 2019-02-22  0:30 UTC (permalink / raw)
  To: Marcel Holtmann, Johan Hedberg
  Cc: linux-bluetooth, linux-kernel, Matthias Kaehlcke, Rajat Jain,
	Heiko Stuebner, Brian Norris

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@chromium.org>
---
 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;
 }
-- 
2.21.0.rc0.258.g878e2cd30e-goog


^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2019-04-01 18:07 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2019-02-22  0:30 [PATCH] Bluetooth: btusb: request wake pin with NOAUTOEN Brian Norris
2019-02-22 18:35 ` Matthias Kaehlcke
2019-03-26 18:48 ` Brian Norris
2019-04-01 18:07   ` Brian Norris

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