lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date:   Thu, 12 Mar 2020 11:10:54 -0700
From:   Abhishek Pandit-Subedi <>
        Abhishek Pandit-Subedi <>,
        "David S. Miller" <>,
        Johan Hedberg <>,,,
        Jakub Kicinski <>
Subject: [PATCH 0/1] Bluetooth: Prioritize sco traffic on slow interfaces

Hi linux-bluetooth,

While investigating supporting Voice over HCI/UART, we discovered that
it is possible for SCO packet deadlines to be missed in some conditions
where large ACL packets are being transferred. For UART, at a baudrate
of 3000000, a single 1024 byte packet will take ~3.4ms to transfer.
Sending two ACL packets of max size would cause us to miss the timing
for SCO (which is 3.75ms) in the worst case.

To mitigate this, we change hci_tx_work to prefer scheduling SCO/eSCO
over ACL/LE and modify the hci_sched_{acl,le} routines so that they will
only send one packet before checking whether a SCO packet is queued. ACL
packets should still get sent at a similar rate (depending on number of
ACL packets supported by controller) since the loop will continue until
there is no more quota left for ACL and LE packets.

To test this patch, I played some music over SCO (open youtube and
a video conference page at the same time) while using an LE keyboard.
There were no discernible slowdowns caused by this change.


Abhishek Pandit-Subedi (1):
  Bluetooth: Prioritize SCO traffic on slow interfaces

 include/net/bluetooth/hci_core.h |  1 +
 net/bluetooth/hci_core.c         | 91 +++++++++++++++++++++++++-------
 2 files changed, 73 insertions(+), 19 deletions(-)


Powered by blists - more mailing lists