[RFC,v3,0/5] Bluetooth: Handle system suspend gracefully

Message

Abhishek Pandit-Subedi Feb. 25, 2020, midnight UTC

Hi linux-bluetooth,

This patch series prepares the Bluetooth controller for system suspend
by disconnecting all devices and preparing the event filter and LE
whitelist with devices that can wake the system from suspend.

The main motivation for doing this is so we can enable Bluetooth as
a wake up source during suspend without it being noisy. Bluetooth should
wake the system when a HID device receives user input but otherwise not
send any events to the host.

This patch series was tested on several Chromebooks with both btusb and
hci_serdev on kernel 4.19. The set of tests was basically the following:
* Reconnects after suspend succeed
* HID devices can wake the system from suspend (needs some related bluez
  changes to call the Set Wake Capable management command)
* System properly pauses and unpauses discovery + advertising around
  suspend
* System does not wake from any events from non wakeable devices

Series 2 has refactored the change into multiple smaller commits as
requested. I tried to simplify some of the whitelist filtering edge
cases but unfortunately it remains quite complex.

Series 3 has refactored it further and should have resolved the
whitelisting complexity in series 2.

Please review and provide any feedback.

Thanks
Abhishek


Changes in v3:
* Refactored to only handle BR/EDR devices
* Split LE changes into its own commit

Changes in v2:
* Moved pm notifier registration into its own patch and moved params out
  of separate suspend_state
* Refactored filters and whitelist settings to its own patch
* Refactored update_white_list to have clearer edge cases
* Add connected devices to whitelist (previously missing corner case)
* Refactored pause discovery + advertising into its own patch

Abhishek Pandit-Subedi (5):
  Bluetooth: Add mgmt op set_wake_capable
  Bluetooth: Handle PM_SUSPEND_PREPARE and PM_POST_SUSPEND
  Bluetooth: Handle BR/EDR devices during suspend
  Bluetooth: Handle LE devices during suspend
  Bluetooth: Pause discovery and advertising during suspend

 include/net/bluetooth/hci.h      |  17 +-
 include/net/bluetooth/hci_core.h |  41 ++++
 include/net/bluetooth/mgmt.h     |   7 +
 net/bluetooth/hci_core.c         |  86 ++++++++
 net/bluetooth/hci_event.c        |  24 +++
 net/bluetooth/hci_request.c      | 327 ++++++++++++++++++++++++++-----
 net/bluetooth/hci_request.h      |   2 +
 net/bluetooth/mgmt.c             |  92 +++++++++
 8 files changed, 536 insertions(+), 60 deletions(-)