Hi Kiran,
On Tue, Apr 1, 2025 at 10:04 PM Kiran K <kiran.k@xxxxxxxxx> wrote:
>
> Reuse the skb buffer provided by the PCIe driver to pass it onto the
> stack, instead of copying it to a new skb.
>
> Fixes: c2b636b3f788 ("Bluetooth: btintel_pcie: Add support for PCIe transport")
> Signed-off-by: Kiran K <kiran.k@xxxxxxxxx>
> ---
> drivers/bluetooth/btintel_pcie.c | 58 ++++++++++++--------------------
> 1 file changed, 22 insertions(+), 36 deletions(-)
>
> diff --git a/drivers/bluetooth/btintel_pcie.c b/drivers/bluetooth/btintel_pcie.c
> index e0b50513403f..ebc36fd33de8 100644
> --- a/drivers/bluetooth/btintel_pcie.c
> +++ b/drivers/bluetooth/btintel_pcie.c
> @@ -947,8 +947,10 @@ static int btintel_pcie_recv_event(struct hci_dev *hdev, struct sk_buff *skb)
> /* This is a debug event that comes from IML and OP image when it
> * starts execution. There is no need pass this event to stack.
Is this logged/sent to monitor at least?
> */
> - if (skb->data[2] == 0x97)
> + if (skb->data[2] == 0x97) {
> + kfree_skb(skb);
> return 0;
> + }
> }
>
> return hci_recv_frame(hdev, skb);
> @@ -964,7 +966,6 @@ static int btintel_pcie_recv_frame(struct btintel_pcie_data *data,
> u8 pkt_type;
> u16 plen;
> u32 pcie_pkt_type;
> - struct sk_buff *new_skb;
> void *pdata;
> struct hci_dev *hdev = data->hdev;
>
> @@ -974,8 +975,7 @@ static int btintel_pcie_recv_frame(struct btintel_pcie_data *data,
> pdata = skb_pull_data(skb, BTINTEL_PCIE_HCI_TYPE_LEN);
> if (!pdata) {
> bt_dev_err(hdev, "Corrupted packet received");
> - ret = -EILSEQ;
> - goto exit_error;
> + goto no_or_short_data;
> }
>
> pcie_pkt_type = get_unaligned_le32(pdata);
> @@ -987,8 +987,7 @@ static int btintel_pcie_recv_frame(struct btintel_pcie_data *data,
> pkt_type = HCI_ACLDATA_PKT;
> } else {
> bt_dev_err(hdev, "ACL packet is too short");
> - ret = -EILSEQ;
> - goto exit_error;
> + goto no_or_short_data;
> }
> break;
>
> @@ -998,8 +997,7 @@ static int btintel_pcie_recv_frame(struct btintel_pcie_data *data,
> pkt_type = HCI_SCODATA_PKT;
> } else {
> bt_dev_err(hdev, "SCO packet is too short");
> - ret = -EILSEQ;
> - goto exit_error;
> + goto no_or_short_data;
> }
> break;
>
> @@ -1009,8 +1007,7 @@ static int btintel_pcie_recv_frame(struct btintel_pcie_data *data,
> pkt_type = HCI_EVENT_PKT;
> } else {
> bt_dev_err(hdev, "Event packet is too short");
> - ret = -EILSEQ;
> - goto exit_error;
> + goto no_or_short_data;
> }
> break;
>
> @@ -1020,45 +1017,40 @@ static int btintel_pcie_recv_frame(struct btintel_pcie_data *data,
> pkt_type = HCI_ISODATA_PKT;
> } else {
> bt_dev_err(hdev, "ISO packet is too short");
> - ret = -EILSEQ;
> - goto exit_error;
> + goto no_or_short_data;
> }
> break;
>
> default:
> bt_dev_err(hdev, "Invalid packet type received: 0x%4.4x",
> pcie_pkt_type);
> - ret = -EINVAL;
> - goto exit_error;
> + goto no_or_short_data;
> }
>
> if (skb->len < plen) {
> bt_dev_err(hdev, "Received corrupted packet. type: 0x%2.2x",
> pkt_type);
> - ret = -EILSEQ;
> - goto exit_error;
> + goto no_or_short_data;
> }
>
> bt_dev_dbg(hdev, "pkt_type: 0x%2.2x len: %u", pkt_type, plen);
>
> - new_skb = bt_skb_alloc(plen, GFP_ATOMIC);
> - if (!new_skb) {
> - bt_dev_err(hdev, "Failed to allocate memory for skb of len: %u",
> - skb->len);
> - ret = -ENOMEM;
> - goto exit_error;
> - }
> -
> - hci_skb_pkt_type(new_skb) = pkt_type;
> - skb_put_data(new_skb, skb->data, plen);
> + hci_skb_pkt_type(skb) = pkt_type;
> hdev->stat.byte_rx += plen;
> + skb_trim(skb, plen);
>
> if (pcie_pkt_type == BTINTEL_PCIE_HCI_EVT_PKT)
> - ret = btintel_pcie_recv_event(hdev, new_skb);
> + ret = btintel_pcie_recv_event(hdev, skb);
> else
> - ret = hci_recv_frame(hdev, new_skb);
> + ret = hci_recv_frame(hdev, skb);
>
> -exit_error:
> +goto out;
> +
> +no_or_short_data:
> + ret = -EILSEQ;
> + kfree_skb(skb);
Don't really like where this is going, having a goto label to cleanup
is fine, having multiple and the having to figure out which one does
what is rather confusing and doesn't help that much, anyway if we got
a negative ret you can probably just make it drop the skb on the if
(ret) statement.
> +out:
> if (ret)
> hdev->stat.err_rx++;
>
> @@ -1192,8 +1184,6 @@ static void btintel_pcie_rx_work(struct work_struct *work)
> struct btintel_pcie_data *data = container_of(work,
> struct btintel_pcie_data, rx_work);
> struct sk_buff *skb;
> - int err;
> - struct hci_dev *hdev = data->hdev;
>
> if (test_bit(BTINTEL_PCIE_HWEXP_INPROGRESS, &data->flags)) {
> /* Unlike usb products, controller will not send hardware
> @@ -1214,11 +1204,7 @@ static void btintel_pcie_rx_work(struct work_struct *work)
>
> /* Process the sk_buf in queue and send to the HCI layer */
> while ((skb = skb_dequeue(&data->rx_skb_q))) {
> - err = btintel_pcie_recv_frame(data, skb);
> - if (err)
> - bt_dev_err(hdev, "Failed to send received frame: %d",
> - err);
> - kfree_skb(skb);
> + btintel_pcie_recv_frame(data, skb);
> }
> }
>
> --
> 2.43.0
>
>
--
Luiz Augusto von Dentz
