Return-Path: <cyrus@holtmann.org>
Date: Thu, 7 Mar 2013 09:11:59 +0200
From: Johan Hedberg <johan.hedberg@gmail.com>
To: Andre Guedes <andre.guedes@openbossa.org>
Cc: linux-bluetooth@vger.kernel.org
Subject: Re: [PATCH 1/4] Bluetooth: Check hci_req_run error code in
 __hci_req_sync
Message-ID: <20130307071159.GA28536@x220>
References: <1362613517-1761-1-git-send-email-andre.guedes@openbossa.org>
 <1362613517-1761-2-git-send-email-andre.guedes@openbossa.org>
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Hi Andre,

On Wed, Mar 06, 2013, Andre Guedes wrote:
> Since hci_req_run will be returning more than one error code, we
> should check its returning value in __hci_req_sync.
> 
> This patch also changes the returning value of hci_req_run in case
> the HCI request is empty.
> 
> Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
> ---
>  net/bluetooth/hci_core.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
> index b6d44a2..a1bbf6d 100644
> --- a/net/bluetooth/hci_core.c
> +++ b/net/bluetooth/hci_core.c
> @@ -101,7 +101,7 @@ static int __hci_req_sync(struct hci_dev *hdev,
>  	func(&req, opt);
>  
>  	err = hci_req_run(&req, hci_req_sync_complete);
> -	if (err < 0) {
> +	if (err == -ENODATA) {
>  		hdev->req_status = 0;
>  		remove_wait_queue(&hdev->req_wait_q, &wait);
>  		/* req_run will fail if the request did not add any
> @@ -112,6 +112,11 @@ static int __hci_req_sync(struct hci_dev *hdev,
>  		 */
>  		return 0;
>  	}
> +	if (err < 0) {
> +		hdev->req_status = HCI_REQ_CANCELED;
> +		remove_wait_queue(&hdev->req_wait_q, &wait);
> +		return err;
> +	}

It might be cleaner to just use one if-branch and something like:

	if (err <  0) {
		/* ENODATA means no commands were added, and it should
		 * not be treated as an error.
		 */
		 if (err == -ENODATA)
		 	err = 0;

		...
	}

> @@ -2453,7 +2458,7 @@ int hci_req_run(struct hci_request *req, hci_req_complete_t complete)
>  
>  	/* Do not allow empty requests */
>  	if (skb_queue_empty(&req->cmd_q))
> -		return -EINVAL;
> +		return -ENODATA;
>  
>  	skb = skb_peek_tail(&req->cmd_q);
>  	bt_cb(skb)->req.complete = complete;

This should probably be in its own patch before the reset, explaining
that ENODATA is a more natural error to be returned in this case.

Johan