Hi Johan,
On Wed, Feb 13, 2013 at 11:50 AM, Johan Hedberg <johan.hedberg@xxxxxxxxx> wrote:
> From: Johan Hedberg <johan.hedberg@xxxxxxxxx>
>
> With these functions it will be possible to declare the start and end of
> a transaction. hci_start_transaction() creates hdev->build_transaction
> which will be used by hci_send_command() to construct a transaction.
> hci_complete_transaction() indicates the end of a transaction with an
> optional complete callback to be called once the transaction is
> complete. The transaction is either moved to hdev->current_transaction
> (if no other transaction is in progress) or appended to
> hdev->transaction_q.
>
> Signed-off-by: Johan Hedberg <johan.hedberg@xxxxxxxxx>
> ---
> include/net/bluetooth/hci_core.h | 5 +++
> net/bluetooth/hci_core.c | 81 ++++++++++++++++++++++++++++++++++++++
> 2 files changed, 86 insertions(+)
>
> diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
> index 0e53032..5cd58f5 100644
> --- a/include/net/bluetooth/hci_core.h
> +++ b/include/net/bluetooth/hci_core.h
> @@ -1058,6 +1058,11 @@ int hci_unregister_cb(struct hci_cb *hcb);
> #define hci_transaction_lock(d) mutex_lock(&d->transaction_lock)
> #define hci_transaction_unlock(d) mutex_unlock(&d->transaction_lock)
>
> +int hci_start_transaction(struct hci_dev *hdev);
> +int hci_complete_transaction(struct hci_dev *hdev,
> + void (*complete)(struct hci_dev *hdev,
> + __u16 last_cmd, int status));
> +
> int hci_send_cmd(struct hci_dev *hdev, __u16 opcode, __u32 plen, void *param);
> void hci_send_acl(struct hci_chan *chan, struct sk_buff *skb, __u16 flags);
> void hci_send_sco(struct hci_conn *conn, struct sk_buff *skb);
> diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
> index 05e2e8b..13c064e 100644
> --- a/net/bluetooth/hci_core.c
> +++ b/net/bluetooth/hci_core.c
> @@ -2196,6 +2196,87 @@ static int hci_send_frame(struct sk_buff *skb)
> return hdev->send(skb);
> }
>
> +int hci_start_transaction(struct hci_dev *hdev)
> +{
> + struct hci_transaction *transaction;
> + int err;
> +
> + hci_transaction_lock(hdev);
> +
> + /* We can't start a new transaction if there's another one in
> + * progress of being built.
> + */
> + if (hdev->build_transaction) {
> + err = -EBUSY;
> + goto unlock;
> + }
> +
> + transaction = kmalloc(sizeof(*transaction), GFP_ATOMIC);
I've failed to see why we need GFP_ATOMIC here. As this code is not
running in any atomic section, we can allocate memory using
GFP_KERNEL.
> + if (!transaction) {
> + err = -ENOMEM;
> + goto unlock;
> + }
> +
> + memset(transaction, 0, sizeof(*transaction));
We can also use kzalloc instead of kmalloc, making this memset unnecessary.
Regards,
Andre
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