Hi Luiz,
>-----Original Message-----
>From: Luiz Augusto von Dentz <luiz.dentz@xxxxxxxxx>
>Sent: Tuesday, October 1, 2024 8:52 PM
>To: linux-bluetooth@xxxxxxxxxxxxxxx
>Subject: [RESEND v3] Bluetooth: btusb: Don't fail external suspend requests
>
>From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
>
>Commit 4e0a1d8b0675
>("Bluetooth: btusb: Don't suspend when there are connections") introduces a
>check for connections to prevent auto-suspend but that actually ignored the
>fact the .suspend callback can be called for external suspend requests which
>Documentation/driver-api/usb/power-management.rst states the following:
>
> 'External suspend calls should never be allowed to fail in this way, only
>autosuspend calls. The driver can tell them apart by applying the
>:c:func:`PMSG_IS_AUTO` macro to the message argument to the ``suspend``
>method; it will return True for internal PM events
> (autosuspend) and False for external PM events.'
>
>In addition to that align system suspend with USB suspend by using
>hci_suspend_dev since otherwise the stack would be expecting events such as
>advertising reports which may not be delivered while the transport is
>suspended.
>
>Fixes: 4e0a1d8b0675 ("Bluetooth: btusb: Don't suspend when there are
>connections")
>Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
Tested-by: Kiran K <kiran.k@xxxxxxxxx>
>---
> drivers/bluetooth/btusb.c | 20 ++++++++++++++++++--
> 1 file changed, 18 insertions(+), 2 deletions(-)
>
>diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c index
>4d3eea414c2a..d14b941bfde8 100644
>--- a/drivers/bluetooth/btusb.c
>+++ b/drivers/bluetooth/btusb.c
>@@ -4075,16 +4075,29 @@ static void btusb_disconnect(struct usb_interface
>*intf) static int btusb_suspend(struct usb_interface *intf, pm_message_t
>message) {
> struct btusb_data *data = usb_get_intfdata(intf);
>+ int err;
>
> BT_DBG("intf %p", intf);
>
>- /* Don't suspend if there are connections */
>- if (hci_conn_count(data->hdev))
>+ /* Don't auto-suspend if there are connections; external suspend calls
>+ * shall never fail.
>+ */
>+ if (PMSG_IS_AUTO(message) && hci_conn_count(data->hdev))
> return -EBUSY;
>
> if (data->suspend_count++)
> return 0;
>
>+ /* Notify Host stack to suspend; this has to be done before stopping
>+ * the traffic since the hci_suspend_dev itself may generate some
>+ * traffic.
>+ */
>+ err = hci_suspend_dev(data->hdev);
>+ if (err) {
>+ data->suspend_count--;
>+ return err;
>+ }
>+
> spin_lock_irq(&data->txlock);
> if (!(PMSG_IS_AUTO(message) && data->tx_in_flight)) {
> set_bit(BTUSB_SUSPENDING, &data->flags); @@ -4092,6
>+4105,7 @@ static int btusb_suspend(struct usb_interface *intf,
>pm_message_t message)
> } else {
> spin_unlock_irq(&data->txlock);
> data->suspend_count--;
>+ hci_resume_dev(data->hdev);
> return -EBUSY;
> }
>
>@@ -4212,6 +4226,8 @@ static int btusb_resume(struct usb_interface *intf)
> spin_unlock_irq(&data->txlock);
> schedule_work(&data->work);
>
>+ hci_resume_dev(data->hdev);
>+
> return 0;
>
> failed:
>--
>2.46.1
>
Thanks,
Kiran
