Re: [PATCH 3/3] Bluetooth: hci_bcm: Ignore deprecated command fail case

[Marcel Holtmann]

Hi Amitesh,

> Broadcom VSC uart_clock_setting is deprecated in
> newer controllers. Ignore error if the controller
> returns invalid or bad request error code.
> 
> Signed-off-by: Amitesh Chandra <amitesh.chandra@xxxxxxxxxxxx>
> Signed-off-by: Manoj Babulal <manoj.babulal@xxxxxxxxxxxx>
> ---
> drivers/bluetooth/hci_bcm.c | 15 +++++++++------
> 1 file changed, 9 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/bluetooth/hci_bcm.c b/drivers/bluetooth/hci_bcm.c
> index 680478f..d316788 100644
> --- a/drivers/bluetooth/hci_bcm.c
> +++ b/drivers/bluetooth/hci_bcm.c
> @@ -158,15 +158,18 @@ static int bcm_set_baudrate(struct hci_uart *hu, unsigned int speed)
> 		skb = __hci_cmd_sync(hdev, 0xfc45, 1, &clock, HCI_INIT_TIMEOUT);
> 		if (IS_ERR(skb)) {
> 			int err = PTR_ERR(skb);
> -			bt_dev_err(hdev, "BCM: failed to write clock (%d)",
> -				   err);
> -			return err;
> +			/* Ignore err if command is deprecated in controller */
> +			if (err != -EBADRQC) {
> +				bt_dev_err(hdev, "BCM: failed to write "
> +						"clock (%d)", err);
> +				return err;
> +			}
> +		} else {
> +			kfree_skb(skb);
> 		}
> -
> -		kfree_skb(skb);
> 	}

So I really disliked try-and-error of HCI commands. Can we know up-front
somehow if the controller supports a command or not. It is a total waste of
time to send a command that might fail. So we better know this before
sending it.

Regards

Marcel