RE: [PATCH] btusb: fix zero BD address problem during stress test

[Amitkumar Karwar]

Hi Marcel,

> From: Amitkumar Karwar [mailto:akarwar@xxxxxxxxxxx]
> Sent: Tuesday, October 18, 2016 6:27 PM
> To: linux-bluetooth@xxxxxxxxxxxxxxx
> Cc: marcel@xxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Cathy Luo;
> Nishant Sarmukadam; Ganapathi Bhat; Amitkumar Karwar
> Subject: [PATCH] btusb: fix zero BD address problem during stress test
> 
> From: Ganapathi Bhat <gbhat@xxxxxxxxxxx>
> 
> We came across a corner case issue during reboot stress test in which
> hciconfig shows BD address is all zero. Reason is we don't get response
> for HCI RESET command during initialization
> 
> The issue is tracked to a race where USB subsystem calls
> btusb_intr_complete() to deliver a data(NOOP frame) received on
> interrupt endpoint. HCI_RUNNING flag is not yet set by bluetooth
> subsystem. So we ignore that frame and return.
> 
> As we missed to resubmit the buffer to interrupt endpoint in this case,
> we don't get response for BT reset command downloaded after this.
> 
> This patch handles the corner case to resolve zero BD address problem.
> 
> Signed-off-by: Ganapathi Bhat <gbhat@xxxxxxxxxxx>
> Signed-off-by: Amitkumar Karwar <akarwar@xxxxxxxxxxx>
> ---
>  drivers/bluetooth/btusb.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
> 
> diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
> index 811f9b9..b5596ac 100644
> --- a/drivers/bluetooth/btusb.c
> +++ b/drivers/bluetooth/btusb.c
> @@ -607,10 +607,7 @@ static void btusb_intr_complete(struct urb *urb)
>  	BT_DBG("%s urb %p status %d count %d", hdev->name, urb, urb-
> >status,
>  	       urb->actual_length);
> 
> -	if (!test_bit(HCI_RUNNING, &hdev->flags))
> -		return;
> -
> -	if (urb->status == 0) {
> +	if (urb->status == 0 && test_bit(HCI_RUNNING, &hdev->flags)) {
>  		hdev->stat.byte_rx += urb->actual_length;
> 
>  		if (btusb_recv_intr(data, urb->transfer_buffer,

Did you get a chance to check this?
Please let us know if you have any review comments.

Regards,
Amitkumar