Re: [PATCH v2] Bluetooth: btusb: Allow firmware re-download when version matches

[Luiz Augusto von Dentz]

Hi Shuai,

On Wed, Apr 29, 2026 at 8:12 AM Shuai Zhang
<shuai.zhang@xxxxxxxxxxxxxxxx> wrote:
>
> The Bluetooth host decides whether to download firmware by reading the
> controller firmware download completion flag and firmware version
> information.
>
> If a USB error occurs during the firmware download process (for example
> due to a USB disconnect), the download is aborted immediately. An
> incomplete firmware transfer does not cause the controller to set the
> download completion flag, but the firmware version information may be
> updated at an early stage of the download process.

Hold on, if the download has been aborted then the version should be
reverted, or rather just update once the firmware loading is complete,
so this indicates there is a bug somewhere that needs fixing, not
worked around.

> In this case, after USB reconnection, the host attempts to re-download
> the firmware because the download completion flag is not set. However,
> since the controller reports the same firmware version as the target
> firmware, the download is skipped. This ultimately results in the
> firmware not being properly updated on the controller.
>
> This change removes the restriction that skips firmware download when
> the versions are equal. It covers scenarios where the USB connection
> can be disconnected at any time and ensures that firmware download can
> be retriggered after USB reconnection, allowing the Bluetooth firmware
> to be correctly and completely updated.
>
> Signed-off-by: Shuai Zhang <shuai.zhang@xxxxxxxxxxxxxxxx>
> ---
> Changes v2:
> - Update code comments and commit message to reflect the correct logic.
> - Align the commit title with upstream conventions.
> - Link v1
>   https://lore.kernel.org/all/20260108074353.1027877-1-shuai.zhang@xxxxxxxxxxxxxxxx/
> ---
>  drivers/bluetooth/btusb.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
> index 572091e60..70abbabea 100644
> --- a/drivers/bluetooth/btusb.c
> +++ b/drivers/bluetooth/btusb.c
> @@ -3550,7 +3550,13 @@ static int btusb_setup_qca_load_rampatch(struct hci_dev *hdev,
>                     "firmware rome 0x%x build 0x%x",
>                     rver_rom, rver_patch, ver_rom, ver_patch);
>
> -       if (rver_rom != ver_rom || rver_patch <= ver_patch) {
> +       /* Allow rampatch when the patch version equals the firmware version.
> +        * A firmware download may be aborted by a transient USB error (e.g.
> +        * disconnect) after the controller updates version info but before
> +        * completion.
> +        * Allowing equal versions enables re-flashing during recovery.
> +        */
> +       if (rver_rom != ver_rom || rver_patch < ver_patch) {

As I said above, this sounds more like a workaround. That said, I
wonder why it would print an error if the version matches, it sounds
to be that if the version matches it should just skip and consider it
has been loaded already in case the actual problem is fixed by setting
the new version only when loading has been completed.

>                 bt_dev_err(hdev, "rampatch file version did not match with firmware");
>                 err = -EINVAL;
>                 goto done;
> --
> 2.34.1
>


-- 
Luiz Augusto von Dentz