atheros bt failed after S3

[AceLan Kao]

[Impact]
BT fails to load firmware after S3. On my system it's atheros' chip, but the same issue can be seen with broadcom's chip, too.
   [542.6274] WARNING: CPU: 0 PID: 20729 at /build/linux-MD8jsN/linux-4.4.0/drivers/base/firmware_class.c:1148 _request_firmware+0x7c2/0xaf0()

The root cause of this issue is request_firmware() is being called at the wrong time.

[Fix]
The fix is from this old thread[1], but the patch didn't be accepted by the maintainer.
It prevents the work queue from being re-created and calls request_firmware() immediately before usermodehelper is fully resumed. Making the workqueue freezable preserves the delay and will postpone the firmware loading time.

[Test Case]
Verified on the machine has this issue, and confirm this patch works.

[Regression Potential]
From what I can see, I think this change should be safe, and after 240 times S3 test, the system and BT functions are still working.

1. http://lists.openwall.net/netdev/2015/05/06/3

[AceLan Kao (acelankao)]

This is a sauce patch, for it didn't be accepted by the maintainer.

[AceLan Kao (acelankao)]

[542.6274] WARNING: CPU: 0 PID: 20729 at /build/linux-MD8jsN/linux-4.4.0/drivers/base/firmware_class.c:1148 _request_firmware+0x7c2/0xaf0()
[542.6276] CPU: 0 PID: 20729 Comm: kworker/u17:0 Tainted: G OE 4.4.0-73-generic #94-Ubuntu
[542.6277] Call Trace:
[542.6277] [<ffffffff813f8493>] dump_stack+0x63/0x90
[542.6277] [<ffffffff81081302>] warn_slowpath_common+0x82/0xc0
[542.6277] [<ffffffff8108144a>] warn_slowpath_null+0x1a/0x20
[542.6277] [<ffffffff81571812>] _request_firmware+0x7c2/0xaf0
[542.6277] [<ffffffff81571b71>] request_firmware+0x31/0x50
[542.6278] [<ffffffffc07a5805>] btusb_setup_qca+0x185/0x3a0 [btusb]
[542.6278] [<ffffffff8156906b>] ? __pm_runtime_resume+0x5b/0x70
[542.6278] [<ffffffffc07a4a49>] btusb_open+0x49/0x250 [btusb]
[542.6278] [<ffffffffc0475cc2>] hci_dev_do_open+0x82/0x580 [bluetooth]
[542.6278] [<ffffffff810ab70d>] ? ttwu_do_activate.constprop.90+0x5d/0x70
[542.6278] [<ffffffffc0477a60>] hci_power_on+0x40/0x1d0 [bluetooth]
[542.6279] [<ffffffff810ecf04>] ? lock_timer_base.isra.22+0x54/0x70
[542.6279] [<ffffffff8109a555>] process_one_work+0x165/0x480
[542.6279] [<ffffffff8109a8bb>] worker_thread+0x4b/0x4c0
[542.6279] [<ffffffff8109a870>] ? process_one_work+0x480/0x480
[542.6279] [<ffffffff810a0be8>] kthread+0xd8/0xf0
[542.6279] [<ffffffff810a0b10>] ? kthread_create_on_node+0x1e0/0x1e0
[542.6279] [<ffffffff8183bd0f>] ret_from_fork+0x3f/0x70
[542.6279] [<ffffffff810a0b10>] ? kthread_create_on_node+0x1e0/0x1e0
[542.6279] ---[ end trace 4e3ab800f10b5115 ]---
[542.6279] bluetooth hci0: firmware: qca/rampatch_usb_00000302.bin will not be loaded
[542.6279] Bluetooth: hci0: failed to request rampatch file: qca/rampatch_usb_00000302.bin (-11)

[Anthony Wong (anthonywong)]

Does the same issue happen on 4.13?

[AceLan Kao (acelankao)]

Upstream claims it's fixed, but we still need to verify it.

[AceLan Kao (acelankao)]

The testing kernel could be found here
http://people.canonical.com/~acelan/bugs/lp1706833/

[Kleber Sacilotto de Souza (kleber-souza)]

This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-xenial' to 'verification-done-xenial'. If the problem still exists, change the tag 'verification-needed-xenial' to 'verification-failed-xenial'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Kai-Heng Feng (kaihengfeng)]

Bluetooth works great in 100 times S3 cycle. No more firmware loading issue.

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 4.4.0-93.116

---------------
linux (4.4.0-93.116) xenial; urgency=low

  * linux: 4.4.0-93.116 -proposed tracker (LP: #1709296)

  * Creating conntrack entry failure with kernel 4.4.0-89 (LP: #1709032)
    - Revert "Revert "netfilter: synproxy: fix conntrackd interaction""
    - netfilter: nf_ct_ext: fix possible panic after nf_ct_extend_unregister

  * CVE-2017-1000112
    - Revert "udp: consistently apply ufo or fragmentation"
    - udp: consistently apply ufo or fragmentation

  * CVE-2017-1000111
    - Revert "net-packet: fix race in packet_set_ring on PACKET_RESERVE"
    - packet: fix tp_reserve race in packet_set_ring

  * kernel BUG at [tty_ldisc_reinit] mm/slub.c! (LP: #1709126)
    - tty: Simplify tty_set_ldisc() exit handling
    - tty: Reset c_line from driver's init_termios
    - tty: Handle NULL tty->ldisc
    - tty: Move tty_ldisc_kill()
    - tty: Use 'disc' for line discipline index name
    - tty: Refactor tty_ldisc_reinit() for reuse
    - tty: Destroy ldisc instance on hangup

  * atheros bt failed after S3 (LP: #1706833)
    - SAUCE: Bluetooth: Make request workqueue freezable

  * The Precision Touchpad(PTP) button sends incorrect event code (LP: #1708372)
    - HID: multitouch: handle external buttons for Precision Touchpads

  * Set CONFIG_SATA_HIGHBANK=y on armhf (LP: #1703430)
    - [Config] CONFIG_SATA_HIGHBANK=y

  * xfs slab objects (memory) leak when xfs shutdown is called (LP: #1706132)
    - xfs: fix xfs_log_ticket leak in xfs_end_io() after fs shutdown

  * Adt tests of src:linux time out often on armhf lxc containers (LP: #1705495)
    - [Packaging] tests -- reduce rebuild test to one flavour

  * CVE-2017-7495
    - ext4: fix data exposure after a crash

  * ubuntu/rsi driver downlink wifi throughput drops to 5-6 Mbps when BT
    keyboard is connected (LP: #1706991)
    - SAUCE: Redpine: enable power save by default for coex mode
    - SAUCE: Redpine: uapsd configuration changes

  * [Hyper-V] hv_netvsc: Exclude non-TCP port numbers from vRSS hashing
    (LP: #1690174)
    - hv_netvsc: Exclude non-TCP port numbers from vRSS hashing

  * ath10k doesn't report full RSSI information (LP: #1706531)
    - ath10k: add per chain RSSI reporting

  * ideapad_laptop don't support v310-14isk (LP: #1705378)
    - platform/x86: ideapad-laptop: Add several models to no_hw_rfkill

  * [8087:0a2b] Failed to load bluetooth firmware(might affect some other Intel
    bt devices) (LP: #1705633)
    - Bluetooth: btintel: Create common Intel Version Read function
    - Bluetooth: Use switch statement for Intel hardware variants
    - Bluetooth: Replace constant hw_variant from Intel Bluetooth firmware
      filename
    - Bluetooth: hci_intel: Fix firmware file name to use hw_variant
    - Bluetooth: btintel: Add MODULE_FIRMWARE entries for iBT 3.5 controllers

  * xhci_hcd: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 2
    comp_code 13 (LP: #1667750)
    - xhci: Bad Ethernet performance plugged in ASM1042A host

  * OpenPower: Some multipaths temporarily have only a single path
    (LP: #1696445)
    - scsi: ses: don't get power status of SES device slot on probe

  ...