[PATCH v6] Bluetooth: qca: Fix delayed hw_error handling due to missing wakeup during SSR

[PATCH v6] Bluetooth: qca: Fix delayed hw_error handling due to missing wakeup during SSR

[Shuai Zhang]

When Bluetooth controller encounters a coredump, it triggers
the Subsystem Restart (SSR) mechanism. The controller first
reports the coredump data, and once the data upload is complete,
it sends a hw_error event. The host relies on this event to
proceed with subsequent recovery actions.

If the host has not finished processing the coredump data
when the hw_error event is received,
it sets a timer to wait until either the data processing is complete
or the timeout expires before handling the event.

The current implementation lacks a wakeup trigger. As a result,
even if the coredump data has already been processed, the host
continues to wait until the timer expires, causing unnecessary
delays in handling the hw_error event.

To fix this issue, adds a `wake_up_bit()` call after the host finishes
processing the coredump data. This ensures that the waiting thread is
promptly notified and can proceed to handle the hw_error event without
waiting for the timeout.

Test case:
- Trigger controller coredump using the command: `hcitool cmd 0x3f 0c 26`.
- Use `btmon` to capture HCI logs.
- Observe the time interval between receiving the hw_error event
and the execution of the power-off sequence in the HCI log.

Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Signed-off-by: Shuai Zhang <shuai.zhang@oss.qualcomm.com>
---
Changes v6:
- Replace wake_up_bit with clear_and_wake_up_bit 
- Link to v5
  https://lore.kernel.org/all/20260409112233.3326467-1-shuai.zhang@oss.qualcomm.com/

Changes v5:
- Replace clear_and_wake_up_bit with wake_up_bit
- Link to v4
  https://lore.kernel.org/all/20260327083258.1398450-1-shuai.zhang@oss.qualcomm.com/

Changes v4:
- add Acked-by signoff
- Link to v3
  https://lore.kernel.org/all/20251107033924.3707495-1-quic_shuaz@quicinc.com/

Changes v3:
- add Fixes tag
- Link to v2
  https://lore.kernel.org/all/20251106140103.1406081-1-quic_shuaz@quicinc.com/

Changes v2:
- Split timeout conversion into a separate patch.
- Clarified commit messages and added test case description.
- Link to v1
  https://lore.kernel.org/all/20251104112601.2670019-1-quic_shuaz@quicinc.com/
---
 drivers/bluetooth/hci_qca.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
index c17a462ae..228a754a9 100644
--- a/drivers/bluetooth/hci_qca.c
+++ b/drivers/bluetooth/hci_qca.c
@@ -1108,7 +1108,7 @@ static void qca_controller_memdump(struct work_struct *work)
 				qca->qca_memdump = NULL;
 				qca->memdump_state = QCA_MEMDUMP_COLLECTED;
 				cancel_delayed_work(&qca->ctrl_memdump_timeout);
-				clear_bit(QCA_MEMDUMP_COLLECTION, &qca->flags);
+				clear_and_wake_up_bit(QCA_MEMDUMP_COLLECTION, &qca->flags);
 				clear_bit(QCA_IBS_DISABLED, &qca->flags);
 				mutex_unlock(&qca->hci_memdump_lock);
 				return;
@@ -1186,7 +1186,7 @@ static void qca_controller_memdump(struct work_struct *work)
 			kfree(qca->qca_memdump);
 			qca->qca_memdump = NULL;
 			qca->memdump_state = QCA_MEMDUMP_COLLECTED;
-			clear_bit(QCA_MEMDUMP_COLLECTION, &qca->flags);
+			clear_and_wake_up_bit(QCA_MEMDUMP_COLLECTION, &qca->flags);
 		}
 
 		mutex_unlock(&qca->hci_memdump_lock);
-- 
2.34.1

Re: [PATCH v6] Bluetooth: qca: Fix delayed hw_error handling due to missing wakeup during SSR

[Paul Menzel]

Dear Shuai,


Thank you for your patch. Just some last style things. It’d be great if 
you could re-flow the commit message to 75 characters per line. This 
would save some lines.

Am 10.04.26 um 10:52 schrieb Shuai Zhang:
> When Bluetooth controller encounters a coredump, it triggers
> the Subsystem Restart (SSR) mechanism. The controller first
> reports the coredump data, and once the data upload is complete,
> it sends a hw_error event. The host relies on this event to
> proceed with subsequent recovery actions.
> 
> If the host has not finished processing the coredump data
> when the hw_error event is received,
> it sets a timer to wait until either the data processing is complete
> or the timeout expires before handling the event.

Maybe mention the timer value?

> The current implementation lacks a wakeup trigger. As a result,
> even if the coredump data has already been processed, the host
> continues to wait until the timer expires, causing unnecessary
> delays in handling the hw_error event.
> 
> To fix this issue, adds a `wake_up_bit()` call after the host finishes

s/adds/add/

Now that you use `clear_and_wake_up_bit()`, this might confuse readers. 
Maybe:

To fix this issue, also wake up the other thread by using 
`clear_and_wake_up_bit()`.

Feel free to ignore though.

> processing the coredump data. This ensures that the waiting thread is
> promptly notified and can proceed to handle the hw_error event without
> waiting for the timeout.
> 
> Test case:
> - Trigger controller coredump using the command: `hcitool cmd 0x3f 0c 26`.

It’d be great if you mentioned one affected controller.

> - Use `btmon` to capture HCI logs.
> - Observe the time interval between receiving the hw_error event
> and the execution of the power-off sequence in the HCI log.

Please paste the logs.

> Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
> Signed-off-by: Shuai Zhang <shuai.zhang@oss.qualcomm.com>
> ---
> Changes v6:
> - Replace wake_up_bit with clear_and_wake_up_bit
> - Link to v5
>    https://lore.kernel.org/all/20260409112233.3326467-1-shuai.zhang@oss.qualcomm.com/
> 
> Changes v5:
> - Replace clear_and_wake_up_bit with wake_up_bit
> - Link to v4
>    https://lore.kernel.org/all/20260327083258.1398450-1-shuai.zhang@oss.qualcomm.com/
> 
> Changes v4:
> - add Acked-by signoff
> - Link to v3
>    https://lore.kernel.org/all/20251107033924.3707495-1-quic_shuaz@quicinc.com/
> 
> Changes v3:
> - add Fixes tag
> - Link to v2
>    https://lore.kernel.org/all/20251106140103.1406081-1-quic_shuaz@quicinc.com/
> 
> Changes v2:
> - Split timeout conversion into a separate patch.
> - Clarified commit messages and added test case description.
> - Link to v1
>    https://lore.kernel.org/all/20251104112601.2670019-1-quic_shuaz@quicinc.com/
> ---
>   drivers/bluetooth/hci_qca.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
> index c17a462ae..228a754a9 100644
> --- a/drivers/bluetooth/hci_qca.c
> +++ b/drivers/bluetooth/hci_qca.c
> @@ -1108,7 +1108,7 @@ static void qca_controller_memdump(struct work_struct *work)
>   				qca->qca_memdump = NULL;
>   				qca->memdump_state = QCA_MEMDUMP_COLLECTED;
>   				cancel_delayed_work(&qca->ctrl_memdump_timeout);
> -				clear_bit(QCA_MEMDUMP_COLLECTION, &qca->flags);
> +				clear_and_wake_up_bit(QCA_MEMDUMP_COLLECTION, &qca->flags);
>   				clear_bit(QCA_IBS_DISABLED, &qca->flags);
>   				mutex_unlock(&qca->hci_memdump_lock);
>   				return;
> @@ -1186,7 +1186,7 @@ static void qca_controller_memdump(struct work_struct *work)
>   			kfree(qca->qca_memdump);
>   			qca->qca_memdump = NULL;
>   			qca->memdump_state = QCA_MEMDUMP_COLLECTED;
> -			clear_bit(QCA_MEMDUMP_COLLECTION, &qca->flags);
> +			clear_and_wake_up_bit(QCA_MEMDUMP_COLLECTION, &qca->flags);
>   		}
>   
>   		mutex_unlock(&qca->hci_memdump_lock);

With the comments above addressed:

Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>


Kind regards,

Paul


PS: gemini/gemini-3.1-pro-preview has some unrelated(?) comments [1]. 
It’d be great if Qualcomm could look into this.


[1]: 
https://sashiko.dev/#/patchset/20260410085202.4128000-1-shuai.zhang%40oss.qualcomm.com

Re: [PATCH v6] Bluetooth: qca: Fix delayed hw_error handling due to missing wakeup during SSR

[Shuai Zhang]

Hi Paul

Thank you for the suggestion. I have updated it in v7.

On 4/10/2026 5:38 PM, Paul Menzel wrote:
> Dear Shuai,
>
>
> Thank you for your patch. Just some last style things. It’d be great 
> if you could re-flow the commit message to 75 characters per line. 
> This would save some lines.
>
> Am 10.04.26 um 10:52 schrieb Shuai Zhang:
>> When Bluetooth controller encounters a coredump, it triggers
>> the Subsystem Restart (SSR) mechanism. The controller first
>> reports the coredump data, and once the data upload is complete,
>> it sends a hw_error event. The host relies on this event to
>> proceed with subsequent recovery actions.
>>
>> If the host has not finished processing the coredump data
>> when the hw_error event is received,
>> it sets a timer to wait until either the data processing is complete
>> or the timeout expires before handling the event.
>
> Maybe mention the timer value?
>
>> The current implementation lacks a wakeup trigger. As a result,
>> even if the coredump data has already been processed, the host
>> continues to wait until the timer expires, causing unnecessary
>> delays in handling the hw_error event.
>>
>> To fix this issue, adds a `wake_up_bit()` call after the host finishes
>
> s/adds/add/
>
> Now that you use `clear_and_wake_up_bit()`, this might confuse 
> readers. Maybe:
>
> To fix this issue, also wake up the other thread by using 
> `clear_and_wake_up_bit()`.
>
> Feel free to ignore though.
>
>> processing the coredump data. This ensures that the waiting thread is
>> promptly notified and can proceed to handle the hw_error event without
>> waiting for the timeout.
>>
>> Test case:
>> - Trigger controller coredump using the command: `hcitool cmd 0x3f 0c 
>> 26`.
>
> It’d be great if you mentioned one affected controller.
>
>> - Use `btmon` to capture HCI logs.
>> - Observe the time interval between receiving the hw_error event
>> and the execution of the power-off sequence in the HCI log.
>
> Please paste the logs.
>
>> Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
>> Signed-off-by: Shuai Zhang <shuai.zhang@oss.qualcomm.com>
>> ---
>> Changes v6:
>> - Replace wake_up_bit with clear_and_wake_up_bit
>> - Link to v5
>> https://lore.kernel.org/all/20260409112233.3326467-1-shuai.zhang@oss.qualcomm.com/
>>
>> Changes v5:
>> - Replace clear_and_wake_up_bit with wake_up_bit
>> - Link to v4
>> https://lore.kernel.org/all/20260327083258.1398450-1-shuai.zhang@oss.qualcomm.com/
>>
>> Changes v4:
>> - add Acked-by signoff
>> - Link to v3
>> https://lore.kernel.org/all/20251107033924.3707495-1-quic_shuaz@quicinc.com/
>>
>> Changes v3:
>> - add Fixes tag
>> - Link to v2
>> https://lore.kernel.org/all/20251106140103.1406081-1-quic_shuaz@quicinc.com/
>>
>> Changes v2:
>> - Split timeout conversion into a separate patch.
>> - Clarified commit messages and added test case description.
>> - Link to v1
>> https://lore.kernel.org/all/20251104112601.2670019-1-quic_shuaz@quicinc.com/
>> ---
>>   drivers/bluetooth/hci_qca.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
>> index c17a462ae..228a754a9 100644
>> --- a/drivers/bluetooth/hci_qca.c
>> +++ b/drivers/bluetooth/hci_qca.c
>> @@ -1108,7 +1108,7 @@ static void qca_controller_memdump(struct 
>> work_struct *work)
>>                   qca->qca_memdump = NULL;
>>                   qca->memdump_state = QCA_MEMDUMP_COLLECTED;
>> cancel_delayed_work(&qca->ctrl_memdump_timeout);
>> -                clear_bit(QCA_MEMDUMP_COLLECTION, &qca->flags);
>> +                clear_and_wake_up_bit(QCA_MEMDUMP_COLLECTION, 
>> &qca->flags);
>>                   clear_bit(QCA_IBS_DISABLED, &qca->flags);
>>                   mutex_unlock(&qca->hci_memdump_lock);
>>                   return;
>> @@ -1186,7 +1186,7 @@ static void qca_controller_memdump(struct 
>> work_struct *work)
>>               kfree(qca->qca_memdump);
>>               qca->qca_memdump = NULL;
>>               qca->memdump_state = QCA_MEMDUMP_COLLECTED;
>> -            clear_bit(QCA_MEMDUMP_COLLECTION, &qca->flags);
>> +            clear_and_wake_up_bit(QCA_MEMDUMP_COLLECTION, &qca->flags);
>>           }
>>             mutex_unlock(&qca->hci_memdump_lock);
>
> With the comments above addressed:
>
> Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
>
>
> Kind regards,
>
> Paul
>
>
> PS: gemini/gemini-3.1-pro-preview has some unrelated(?) comments [1]. 
> It’d be great if Qualcomm could look into this.
>
>
> [1]: 
> https://sashiko.dev/#/patchset/20260410085202.4128000-1-shuai.zhang%40oss.qualcomm.com 
>


Thanks，
shuai

RE: [v6] Bluetooth: qca: Fix delayed hw_error handling due to missing wakeup during SSR

[bluez.test.bot]

[-- Attachment #1: Type: text/plain, Size: 6870 bytes --]

This is automated email and please do not reply to this email!

Dear submitter,

Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=1079639

---Test result---

Test Summary:
CheckPatch                    PENDING   0.60 seconds
GitLint                       PENDING   0.38 seconds
SubjectPrefix                 PASS      0.06 seconds
BuildKernel                   PASS      26.26 seconds
CheckAllWarning               PASS      28.59 seconds
CheckSparse                   PASS      27.23 seconds
BuildKernel32                 PASS      25.36 seconds
TestRunnerSetup               PASS      572.56 seconds
TestRunner_l2cap-tester       PASS      27.69 seconds
TestRunner_iso-tester         PASS      37.70 seconds
TestRunner_bnep-tester        PASS      6.44 seconds
TestRunner_mgmt-tester        FAIL      114.46 seconds
TestRunner_rfcomm-tester      PASS      9.29 seconds
TestRunner_sco-tester         FAIL      14.40 seconds
TestRunner_ioctl-tester       PASS      10.15 seconds
TestRunner_mesh-tester        FAIL      12.57 seconds
TestRunner_smp-tester         PASS      8.46 seconds
TestRunner_userchan-tester    PASS      6.78 seconds
TestRunner_6lowpan-tester     FAIL      8.63 seconds
IncrementalBuild              PENDING   0.42 seconds

Details
##############################
Test: CheckPatch - PENDING
Desc: Run checkpatch.pl script
Output:

##############################
Test: GitLint - PENDING
Desc: Run gitlint
Output:

##############################
Test: TestRunner_mgmt-tester - FAIL
Desc: Run mgmt-tester with test-runner
Output:
Total: 494, Passed: 489 (99.0%), Failed: 1, Not Run: 4

Failed Test Cases
Read Exp Feature - Success                           Failed       0.107 seconds
##############################
Test: TestRunner_sco-tester - FAIL
Desc: Run sco-tester with test-runner
Output:
WARNING: possible circular locking dependency detected
7.0.0-rc2-gecb16c274d1d #1 Not tainted
------------------------------------------------------
kworker/u5:2/117 is trying to acquire lock:
ffff888001945240 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: sco_connect_cfm+0x358/0x8d0

but task is already holding lock:
ffff8880025fb220 (&conn->lock){+.+.}-{3:3}, at: sco_connect_cfm+0x22d/0x8d0

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&conn->lock){+.+.}-{3:3}:
       lock_acquire+0xf7/0x2c0
       _raw_spin_lock+0x2a/0x40
       sco_sock_connect+0x4d7/0x1280
       __sys_connect+0x1a3/0x260
       __x64_sys_connect+0x6e/0xb0
       do_syscall_64+0xa0/0x570
       entry_SYSCALL_64_after_hwframe+0x74/0x7c

-> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}:
       check_prev_add+0xe9/0xc70
       __lock_acquire+0x1457/0x1df0
       lock_acquire+0xf7/0x2c0
       lock_sock_nested+0x36/0xd0
       sco_connect_cfm+0x358/0x8d0
       hci_sync_conn_complete_evt+0x3d3/0x8e0
       hci_event_packet+0x74f/0xb10
       hci_rx_work+0x398/0xd00
       process_scheduled_works+0xb16/0x1ac0
       worker_thread+0x4ff/0xba0
       kthread+0x368/0x490
       ret_from_fork+0x498/0x7e0
       ret_from_fork_asm+0x19/0x30

other info that might help us debug this:

...
BUG: sleeping function called from invalid context at net/core/sock.c:3782
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 117, name: kworker/u5:2
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
INFO: lockdep is turned off.
CPU: 0 UID: 0 PID: 117 Comm: kworker/u5:2 Not tainted 7.0.0-rc2-gecb16c274d1d #1 PREEMPT(lazy) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-1ubuntu1.1 04/01/2014
Workqueue: hci0 hci_rx_work
Call Trace:
 <TASK>
 dump_stack_lvl+0x49/0x60
 __might_resched+0x2ea/0x500
 lock_sock_nested+0x47/0xd0
 ? sco_connect_cfm+0x358/0x8d0
 sco_connect_cfm+0x358/0x8d0
 ? hci_debugfs_create_conn+0x190/0x210
 ? __pfx_sco_connect_cfm+0x10/0x10
 hci_sync_conn_complete_evt+0x3d3/0x8e0
 hci_event_packet+0x74f/0xb10
 ? __pfx_hci_sync_conn_complete_evt+0x10/0x10
 ? __pfx_hci_event_packet+0x10/0x10
 ? mark_held_locks+0x49/0x80
 ? lockdep_hardirqs_on_prepare+0xd4/0x180
 ? _raw_spin_unlock_irqrestore+0x2c/0x50
 hci_rx_work+0x398/0xd00
 process_scheduled_works+0xb16/0x1ac0
 ? __pfx_process_scheduled_works+0x10/0x10
 ? lock_acquire+0xf7/0x2c0
 ? lock_is_held_type+0x9b/0x110
 ? __pfx_hci_rx_work+0x10/0x10
 worker_thread+0x4ff/0xba0
 ? _raw_spin_unlock_irqrestore+0x2c/0x50
 ? __pfx_worker_thread+0x10/0x10
 kthread+0x368/0x490
 ? _raw_spin_unlock_irq+0x23/0x40
 ? __pfx_kthread+0x10/0x10
 ret_from_fork+0x498/0x7e0
 ? __pfx_ret_from_fork+0x10/0x10
 ? __switch_to+0x9e4/0xe50
 ? __switch_to_asm+0x32/0x60
...
Total: 30, Passed: 30 (100.0%), Failed: 0, Not Run: 0
##############################
Test: TestRunner_mesh-tester - FAIL
Desc: Run mesh-tester with test-runner
Output:
Total: 10, Passed: 8 (80.0%), Failed: 2, Not Run: 0

Failed Test Cases
Mesh - Send cancel - 1                               Timed out    2.724 seconds
Mesh - Send cancel - 2                               Timed out    1.997 seconds
##############################
Test: TestRunner_6lowpan-tester - FAIL
Desc: Run 6lowpan-tester with test-runner
Output:
WARNING: possible circular locking dependency detected
7.0.0-rc2-gecb16c274d1d #1 Not tainted
------------------------------------------------------
kworker/0:1/11 is trying to acquire lock:
ffff888002492940 ((wq_completion)hci0#2){+.+.}-{0:0}, at: touch_wq_lockdep_map+0x75/0x180

but task is already holding lock:
ffffffffa504d720 (rtnl_mutex){+.+.}-{4:4}, at: lowpan_unregister_netdev+0xd/0x30

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (rtnl_mutex){+.+.}-{4:4}:
       lock_acquire+0xf7/0x2c0
       __mutex_lock+0x16b/0x1fc0
       lowpan_register_netdev+0x11/0x30
       chan_ready_cb+0x836/0xd00
       l2cap_recv_frame+0x6a06/0x8920
       l2cap_recv_acldata+0x790/0xdf0
       hci_rx_work+0x500/0xd00
       process_scheduled_works+0xb16/0x1ac0
       worker_thread+0x4ff/0xba0
       kthread+0x368/0x490
       ret_from_fork+0x498/0x7e0
       ret_from_fork_asm+0x19/0x30

-> #3 (&chan->lock#3/1){+.+.}-{4:4}:
       lock_acquire+0xf7/0x2c0
       __mutex_lock+0x16b/0x1fc0
       l2cap_chan_connect+0x74e/0x1980
       lowpan_control_write+0x523/0x660
       full_proxy_write+0x10b/0x190
       vfs_write+0x1c0/0xf60
       ksys_write+0xf1/0x1d0
       do_syscall_64+0xa0/0x570
       entry_SYSCALL_64_after_hwframe+0x74/0x7c

-> #2 (&conn->lock){+.+.}-{4:4}:
...
Total: 8, Passed: 8 (100.0%), Failed: 0, Not Run: 0
##############################
Test: IncrementalBuild - PENDING
Desc: Incremental build with the patches in the series
Output:



https://github.com/bluez/bluetooth-next/pull/60

---
Regards,
Linux Bluetooth

Re: [PATCH v6] Bluetooth: qca: Fix delayed hw_error handling due to missing wakeup during SSR

[patchwork-bot+bluetooth]

Hello:

This patch was applied to bluetooth/bluetooth-next.git (master)
by Luiz Augusto von Dentz <luiz.von.dentz@intel.com>:

On Fri, 10 Apr 2026 16:52:02 +0800 you wrote:
> When Bluetooth controller encounters a coredump, it triggers
> the Subsystem Restart (SSR) mechanism. The controller first
> reports the coredump data, and once the data upload is complete,
> it sends a hw_error event. The host relies on this event to
> proceed with subsequent recovery actions.
> 
> If the host has not finished processing the coredump data
> when the hw_error event is received,
> it sets a timer to wait until either the data processing is complete
> or the timeout expires before handling the event.
> 
> [...]

Here is the summary with links:
  - [v6] Bluetooth: qca: Fix delayed hw_error handling due to missing wakeup during SSR
    https://git.kernel.org/bluetooth/bluetooth-next/c/9f07d5d04826

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
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