** Also affects: linux-oem-6.11 (Ubuntu Noble)
   Importance: Undecided
       Status: New

** Changed in: linux-oem-6.11 (Ubuntu Noble)
     Assignee: (unassigned) => Leo Lin (0xff07)

-- 
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux-oem-6.11 in Ubuntu.
https://bugs.launchpad.net/bugs/2092473

Title:
  [SRU] Fix system hang issue caused by the btmtk driver

Status in HWE Next:
  New
Status in linux-oem-6.11 package in Ubuntu:
  New
Status in linux-oem-6.11 source package in Noble:
  New

Bug description:
  [ Impact ]

  On some machine with Mediatek USB bluetooth controller, activate
  scanning will lead to system hang. This is due to unexpected null
  pointer dereference in the set up flow.

  [ Fix ]

  Cherry-pick one commit from mainline linux:

      61c5a3def90a (Bluetooth: btmtk: adjust the position to init iso
  data anchor)

  [ Test ]

  1. Boot into the kenrel
  2. Run bluetoothctl
  3. In the bluetoothctl shell, run "scan on"
  4. The MTK bluetooth usb device should be able to scan, and system should not 
hang.

  [ Where problems could occur ]

  The call trace in the upstream commit shows that the intention for the
  patch is to fix what was happening unexpected USB disconnect. However,
  here in 6.11-oem the btusb_mtk_disconnect() in the call trace, which
  is what usb_kill_anchored_urbs() an uninitailized usb anchor and lead
  to the error, is not even implemented.

  From the call trace collected we collected, the code path seems to be
  btusb_disconnect()->hci_unregister_dev()->btmtk shutdwn callback.
  However they all lead to calling the usb_kill_anchored_urbs() before
  the same btmtk_data->isopkt_anchor is initialized by the
  init_usb_anchor(). That's probably why the patch could fix the issue
  here as well.

  The upstream patch author didn't state when or why such "unexpected
  USB disconnect during setup" might happen.

To manage notifications about this bug go to:
https://bugs.launchpad.net/hwe-next/+bug/2092473/+subscriptions


-- 
Mailing list: https://launchpad.net/~kernel-packages
Post to     : kernel-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~kernel-packages
More help   : https://help.launchpad.net/ListHelp

Reply via email to