[PATCH] UBUNTU: SAUCE: Bluetooth: Make request workqueue freezable

[Stefan Bader]

On 27.07.2017 04:36, AceLan Kao wrote:
> From: Laura Abbott <labbott at fedoraproject.org>
> 
> BugLink: http://bugs.launchpad.net/bugs/1706833
> 
> We've received a number of reports of warnings when coming
> out of suspend with certain bluetooth firmware configurations:
> 
> WARNING: CPU: 3 PID: 3280 at drivers/base/firmware_class.c:1126
> _request_firmware+0x558/0x810()
> Modules linked in: ccm ip6t_rpfilter ip6t_REJECT nf_reject_ipv6
> xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter
> ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6
> ip6table_mangle ip6table_security ip6table_raw ip6table_filter
> ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4
> nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw
> binfmt_misc bnep intel_rapl iosf_mbi arc4 x86_pkg_temp_thermal
> snd_hda_codec_hdmi coretemp kvm_intel joydev snd_hda_codec_realtek
> iwldvm snd_hda_codec_generic kvm iTCO_wdt mac80211 iTCO_vendor_support
> snd_hda_intel snd_hda_controller snd_hda_codec crct10dif_pclmul
> snd_hwdep crc32_pclmul snd_seq crc32c_intel ghash_clmulni_intel uvcvideo
> snd_seq_device iwlwifi btusb videobuf2_vmalloc snd_pcm videobuf2_core
>  serio_raw bluetooth cfg80211 videobuf2_memops sdhci_pci v4l2_common
> videodev thinkpad_acpi sdhci i2c_i801 lpc_ich mfd_core wacom mmc_core
> media snd_timer tpm_tis hid_logitech_hidpp wmi tpm rfkill snd mei_me mei
> shpchp soundcore nfsd auth_rpcgss nfs_acl lockd grace sunrpc i915
> i2c_algo_bit drm_kms_helper e1000e drm hid_logitech_dj ptp pps_core
> video
> CPU: 3 PID: 3280 Comm: kworker/u17:0 Not tainted 3.19.3-200.fc21.x86_64
> Hardware name: LENOVO 343522U/343522U, BIOS GCET96WW (2.56 ) 10/22/2013
> Workqueue: hci0 hci_power_on [bluetooth]
>  0000000000000000 0000000089944328 ffff88040acffb78 ffffffff8176e215
>  0000000000000000 0000000000000000 ffff88040acffbb8 ffffffff8109bc1a
>  0000000000000000 ffff88040acffcd0 00000000fffffff5 ffff8804076bac40
> Call Trace:
>  [<ffffffff8176e215>] dump_stack+0x45/0x57
>  [<ffffffff8109bc1a>] warn_slowpath_common+0x8a/0xc0
>  [<ffffffff8109bd4a>] warn_slowpath_null+0x1a/0x20
>  [<ffffffff814dbe78>] _request_firmware+0x558/0x810
>  [<ffffffff814dc165>] request_firmware+0x35/0x50
>  [<ffffffffa03a7886>] btusb_setup_bcm_patchram+0x86/0x590 [btusb]
>  [<ffffffff814d40e6>] ? rpm_idle+0xd6/0x230
>  [<ffffffffa04d4801>] hci_dev_do_open+0xe1/0xa90 [bluetooth]
>  [<ffffffff810c51dd>] ? ttwu_do_activate.constprop.90+0x5d/0x70
>  [<ffffffffa04d5980>] hci_power_on+0x40/0x200 [bluetooth]
>  [<ffffffff810b487c>] process_one_work+0x14c/0x3f0
>  [<ffffffff810b52f3>] worker_thread+0x53/0x470
>  [<ffffffff810b52a0>] ? rescuer_thread+0x300/0x300
>  [<ffffffff810ba548>] kthread+0xd8/0xf0
>  [<ffffffff810ba470>] ? kthread_create_on_node+0x1b0/0x1b0
>  [<ffffffff81774958>] ret_from_fork+0x58/0x90
>  [<ffffffff810ba470>] ? kthread_create_on_node+0x1b0/0x1b0
> 
> This occurs after every resume.
> 
> When resuming, the bluetooth stack calls hci_register_dev,
> allocates a new workqueue, and immediately schedules the
> power_on on the newly created workqueue. Since the new
> workqueue is not freezable, the work runs immediately and
> triggers the warning since resume is still happening and
> usermodehelper has not yet been re-enabled. Fix this by
> making the request workqueue freezable. This ensures
> the work will not run until unfreezing occurs and usermodehelper
> is re-enabled.
> 
> Signed-off-by: Laura Abbott <labbott at fedoraproject.org>
> Signed-off-by: AceLan Kao <acelan.kao at canonical.com>
> ---

Why was this change not accepted upstream? Is every laptop with bluetooth
affected? Did you do some broader testing (not only on that one hw)?

-Stefan
>  net/bluetooth/hci_core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
> index eea796c..780a76c 100644
> --- a/net/bluetooth/hci_core.c
> +++ b/net/bluetooth/hci_core.c
> @@ -3365,7 +3365,7 @@ int hci_register_dev(struct hci_dev *hdev)
>  	}
>  
>  	hdev->req_workqueue = alloc_workqueue("%s", WQ_HIGHPRI | WQ_UNBOUND |
> -					      WQ_MEM_RECLAIM, 1, hdev->name);
> +					      WQ_MEM_RECLAIM | WQ_FREEZABLE, 1, hdev->name);
>  	if (!hdev->req_workqueue) {
>  		destroy_workqueue(hdev->workqueue);
>  		error = -ENOMEM;
> 


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