Re: [PATCH] Bluetooth: btusb: Add a module parameter ignore_id for debugging

[Hui Wang <hui.wang@canonical.com>]

On 2020/8/3 下午2:45, Marcel Holtmann wrote:
> Hi Hui,
>
>>>> There is always an on-board usb bluetooth hci on the laptops, if
>>>> the bluetooth function doesn't work well like a bt headset can't work
>>>> with HSP/HFP mode, we often plug an external usb BT hci to verify if
>>>> that headset could work with the exteral BT hci or not, in this
>>>> situation, there will be 2 hcis (hci0 and hci1) in the system, and
>>>> so far, the gnome can't handle the hci1 well so we met lots of
>>>> problems when debugging with hci1 under gnome.
>>>>
>>>> After adding this new module parameter, we could ban the on-board
>>>> usb hci by putting btusb.ignore_id=idVendor,idProduct to the bootargs,
>>>> then the external usb hci will be hci0 and there is only one hci
>>>> in the system. We could easily debug with the external usb bluetooth
>>>> hci after this change.
>>>>
>>>> Signed-off-by: Hui Wang <hui.wang@canonical.com>
>>>> ---
>>>> drivers/bluetooth/btusb.c | 11 +++++++++++
>>>> 1 file changed, 11 insertions(+)
>>> please use this instead.
>>>
>>> echo “vvvv pppp 0 08fd 0002" > /sys/bus/usb/drivers/foo/new_id
>> Thanks,  but to run the command above,  the system should boot up first.  After the system boot up, the btusb is already loaded and and the on-board hci is already driven by btusb. looks like it is too late to run that command for on-board hci.
> then unload the module first or blacklist the module.

Sorry,  still don't understand.  After unload/blacklist the module, 
there will be no /sys/bus/usb/drivers/foo/new_id. Once we load the 
module, the on-board hci will be driven by the module immediately. Looks 
like setting new_id is only useful for USB dongles, for on-board usb 
devices,  I have no idea how to use the new_id.

Thanks,

Hui.

>
> Regards
>
> Marcel
>