Re: [PATCH v5] Bluetooth: qca: Fix delayed hw_error handling due to missing wakeup during SSR

[Bartosz Golaszewski]

On Thu, 9 Apr 2026 13:22:33 +0200, Shuai Zhang
<shuai.zhang@xxxxxxxxxxxxxxxx> said:
> 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.
>
> Signed-off-by: Shuai Zhang <shuai.zhang@xxxxxxxxxxxxxxxx>
> ---

Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxxxxxxxx>