Re: [PATCH v2] Bluetooth: hci_qca: Use 100 ms SSR delay for rampatch and NVM loading

[Dmitry Baryshkov]

On Mon, May 25, 2026 at 02:51:56PM +0800, Shuai Zhang wrote:
> When bt_en is pulled high by hardware, the host does not re-download
> the firmware after SSR. The controller loads the rampatch and NVM
> internally.
> 
> On HMT chip, the rampatch is ~264 KB and the NVM is ~9.4 KB. The

What is HMT? Don't use abbreviations which are not known outside of your
company.

> loading process takes approximately 70 ms. The previous 50 ms delay is
> too short, causing the controller to not respond to the reset command
> sent by the host, which leads to BT initialization failure:
> 
>  Bluetooth: hci0: QCA memdump Done, received 458752, total 458752
>  Bluetooth: hci0: mem_dump_status: 2
>  Bluetooth: hci0: Opcode 0x0c03 failed: -110
> 
> Increase the delay to 100 ms, which was confirmed as a safe value by
> the controller, to ensure the controller has finished loading the
> firmware before the host sends commands.
> 
> Steps to reproduce:
> 1. Trigger SSR and wait for SSR to complete:
>    hcitool cmd 0x3f 0c 26
> 2. Run "bluetoothctl power on" and observe that BT fails to start.
> 
> Fixes: fce1a9244a0f ("Bluetooth: hci_qca: Fix SSR (SubSystem Restart) fail when BT_EN is pulled up by hw")
> Cc: stable@xxxxxxxxxxxxxxx
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxxxxxxxx>
> Signed-off-by: Shuai Zhang <shuai.zhang@xxxxxxxxxxxxxxxx>

-- 
With best wishes
Dmitry