> -----Original Message----- > From: Limonciello, Mario > Sent: Wednesday, August 7, 2019 3:43 PM > To: 'Christian Kellner'; linux-bluetooth@xxxxxxxxxxxxxxx > Subject: RE: BT advertising packets and s2idle issue > > > -----Original Message----- > > From: Christian Kellner <ckellner@xxxxxxxxxx> > > Sent: Monday, July 29, 2019 9:33 AM > > To: linux-bluetooth@xxxxxxxxxxxxxxx > > Cc: Limonciello, Mario > > Subject: BT advertising packets and s2idle issue > > > > > > [EXTERNAL EMAIL] > > > > > > Hi all, > > > > I have been wondering what to do about the bug that advertising packet > > will wake systems from s2idle when a device was previously paired with > > the HCI_AUTO_CONN_ALWAYS flag (kernel bug #200039[1]). I was thinking of > > creating a patch for bluez that would create a "delay lock"[2] and > > de-register any such device from the kernel before entering s2idle, but > > I wanted to check first if that is the best approach. > > In comment #27 it is suggested that using a "LE Privacy v1.2" feature > > could fix the issue as well. Is there some more information about this > > available somewhere? II can help out with development and testing as I > > have an affected system myself. > > > > Cheers, > > CK > > > > [1] https://bugzilla.kernel.org/show_bug.cgi?id=200039 > > [2] https://www.freedesktop.org/wiki/Software/systemd/inhibit/ > > > > -- > > Dr. Christian J. Kellner > > Desktop Hardware Enablement > > Red Hat > > If I'm not mistaken, even unpaired LE devices can cause the wakeup. Any device > with an advertisement report will cause the wakeup. So de-registering all devices > from kernel before entering s2idle wouldn't solve the problem. > > My opinion is there should be a dedicated kernel freeze handler that does the > following: > 1) If LE Privacy 1.2 "in use", handle regular suspend/resume flow > 2) If LE Privacy 1.1in use, power off the radio in freeze, power back on in resume. > > For now, since LE privacy 1.2 not yet enabled, this would at least help with this > situation as reported. > > Of course this will mean BT devices can't wake the system anymore if s2i, so > maybe > the behavior should be put behind a module parameter or sysfs file. > > BLE devices are so prevalent though; I find it a hard time imagining anyone wants > it > the way it exists today. Another approach to this may be to submit a revert to the kernel for this commit: https://github.com/torvalds/linux/commit/a0085f2510e8976614ad8f766b209448b385492f until LE privacy support is in place. This seems a regression to me that the system wakes up from any BLE traffic after that commit.
