Commit 610712298b11b2914be00b35abe9326b5dbb62c8 Breaks Bluetooth discovery

From: Walt Holman
Date: Sat Oct 12 2024 - 09:42:43 EST


Recent 6.12.0-rc kernels include the following commit:

commit 610712298b11b2914be00b35abe9326b5dbb62c8
Author: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
Date: Tue Oct 1 11:21:37 2024 -0400

Bluetooth: btusb: Don't fail external suspend requests

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>

This breaks bluetooth on my ASUS ROG GA605WI laptop. I am using a
Qualcomm WCN785x Wi-Fi chip with Quectel Bluetooth. Reverting the
above commit fixes discovery and connection issues with bluetooth on
my laptop.