Re: [PATCH v1] Bluetooth: hci_qca: Add support for controller debug logs.

[Matthias Kaehlcke <mka@chromium.org>]

Hi Balakrishna,

On Mon, Oct 01, 2018 at 07:21:02PM +0530, Balakrishna Godavarthi wrote:
> This patch will prevent error messages splashing on console.
> 
> [   78.426697] Bluetooth: hci_core.c:hci_acldata_packet() hci0: ACL packet for unknown connection handle 3804
> [   78.436682] Bluetooth: hci_core.c:hci_acldata_packet() hci0: ACL packet for unknown connection handle 3804
> [   78.446639] Bluetooth: hci_core.c:hci_acldata_packet() hci0: ACL packet for unknown connection handle 3804
> [   78.456596] Bluetooth: hci_core.c:hci_acldata_packet() hci0: ACL packet for unknown connection handle 3804
> 
> QCA wcn3990 will send the debug logs in the form of ACL packets.
> While decoding packet in qca_recv(), marking the received debug log
> packet as diagnostic packet.
> 
> Signed-off-by: Harish Bandi <c-hbandi@codeaurora.org>
> Signed-off-by: Balakrishna Godavarthi <bgodavar@codeaurora.org>
> ---
>  drivers/bluetooth/hci_qca.c | 27 ++++++++++++++++++++++++++-
>  1 file changed, 26 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/bluetooth/hci_qca.c b/drivers/bluetooth/hci_qca.c
> index d98ed0442201..a00910aaed54 100644
> --- a/drivers/bluetooth/hci_qca.c
> +++ b/drivers/bluetooth/hci_qca.c
> @@ -63,6 +63,10 @@
>  /* susclk rate */
>  #define SUSCLK_RATE_32KHZ	32768
>  
> +/* Controller debug log header */
> +#define QCA_DEBUG_HDR_MSB	0xDC
> +#define QCA_DEBUG_HDR_LSB	0x2E
> +
>  /* HCI_IBS transmit side sleep protocol states */
>  enum tx_ibs_states {
>  	HCI_IBS_TX_ASLEEP,
> @@ -849,6 +853,20 @@ static int qca_ibs_wake_ack(struct hci_dev *hdev, struct sk_buff *skb)
>  	return 0;
>  }
>  
> +static int qca_recv_acl_data(struct hci_dev *hdev, struct sk_buff *skb)
> +{
> +	/* We receive debug logs from chip as an ACL packets.
> +	 * Instead of sending the data to ACL to decode the
> +	 * received data, we are pushing them to the above layers
> +	 * as a diagnostic packet.
> +	 */
> +	if ((skb->len > 2) && (skb->data[0] == QCA_DEBUG_HDR_MSB) &&
> +	    (skb->data[1] == QCA_DEBUG_HDR_LSB))
> +		return hci_recv_diag(hdev, skb);
> +	else
> +		return hci_recv_frame(hdev, skb);

nit: you could just do hci_recv_frame() after the if branch, instead
of doing it in 'else'. That would make it clearer at first sight that
the QCA debug packets are a special case and other packets normal
operation.

> +}
> +
>  #define QCA_IBS_SLEEP_IND_EVENT \
>  	.type = HCI_IBS_SLEEP_IND, \
>  	.hlen = 0, \
> @@ -870,13 +888,20 @@ static int qca_ibs_wake_ack(struct hci_dev *hdev, struct sk_buff *skb)
>  	.lsize = 0, \
>  	.maxlen = HCI_MAX_IBS_SIZE
>  
> +#define QCA_RECV_ACL_DATA \
> +	.type = HCI_ACLDATA_PKT, \
> +	.hlen = HCI_ACL_HDR_SIZE, \
> +	.loff = 2, \
> +	.lsize = 2, \
> +	.maxlen = HCI_MAX_FRAME_SIZE

Is there any actual advantage of adding this 'macro' instead of just
using H4_RECV_ACL, which is exactly the same?

>  static const struct h4_recv_pkt qca_recv_pkts[] = {
> -	{ H4_RECV_ACL,             .recv = hci_recv_frame    },
>  	{ H4_RECV_SCO,             .recv = hci_recv_frame    },
>  	{ H4_RECV_EVENT,           .recv = hci_recv_frame    },
>  	{ QCA_IBS_WAKE_IND_EVENT,  .recv = qca_ibs_wake_ind  },
>  	{ QCA_IBS_WAKE_ACK_EVENT,  .recv = qca_ibs_wake_ack  },
>  	{ QCA_IBS_SLEEP_IND_EVENT, .recv = qca_ibs_sleep_ind },
> +	{ QCA_RECV_ACL_DATA,       .recv = qca_recv_acl_data },
>  };
>  
>  static int qca_recv(struct hci_uart *hu, const void *data, int count)