On Wednesday 09 September 2020 17:42:01 Joseph Hwang wrote:
> It is desirable to define the HCI packet payload sizes of
> USB alternate settings so that they can be exposed to user
> space.
>
> Reviewed-by: Alain Michaud <alainm@xxxxxxxxxxxx>
> Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@xxxxxxxxxxxx>
> Signed-off-by: Joseph Hwang <josephsih@xxxxxxxxxxxx>
> ---
>
> Changes in v2:
> - 1/2: Used sco_mtu instead of a new sco_pkt_len member in hdev.
> - 1/2: Do not overwrite hdev->sco_mtu in hci_cc_read_buffer_size
> if it has been set in the USB interface.
> - 2/2: Used BT_SNDMTU/BT_RCVMTU instead of creating a new opt name.
> - 2/2: Used the existing conn->mtu instead of creating a new member
> in struct sco_pinfo.
> - 2/2: Noted that the old SCO_OPTIONS in sco_sock_getsockopt_old()
> would just work as it uses sco_pi(sk)->conn->mtu.
>
> drivers/bluetooth/btusb.c | 43 +++++++++++++++++++++++++++++----------
> net/bluetooth/hci_event.c | 7 ++++++-
> 2 files changed, 38 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
> index fe80588c7bd3a8..a710233382afff 100644
> --- a/drivers/bluetooth/btusb.c
> +++ b/drivers/bluetooth/btusb.c
> @@ -459,6 +459,22 @@ static const struct dmi_system_id btusb_needs_reset_resume_table[] = {
> #define BTUSB_WAKEUP_DISABLE 14
> #define BTUSB_USE_ALT1_FOR_WBS 15
>
> +/* Per core spec 5, vol 4, part B, table 2.1,
> + * list the hci packet payload sizes for various ALT settings.
> + * This is used to set the packet length for the wideband speech.
> + * If a controller does not probe its usb alt setting, the default
> + * value will be 0. Any clients at upper layers should interpret it
> + * as a default value and set a proper packet length accordingly.
> + *
> + * To calculate the HCI packet payload length:
> + * for alternate settings 1 - 5:
> + * hci_packet_size = suggested_max_packet_size * 3 (packets) -
> + * 3 (HCI header octets)
> + * for alternate setting 6:
> + * hci_packet_size = suggested_max_packet_size - 3 (HCI header octets)
Hello! What is value for 'suggested_max_packet_size' used in above
calculation algorithm?
> + */
> +static const int hci_packet_size_usb_alt[] = { 0, 24, 48, 72, 96, 144, 60 };
> +
> struct btusb_data {
> struct hci_dev *hdev;
> struct usb_device *udev;
> @@ -3959,6 +3975,15 @@ static int btusb_probe(struct usb_interface *intf,
> hdev->notify = btusb_notify;
> hdev->prevent_wake = btusb_prevent_wake;
>
> + if (id->driver_info & BTUSB_AMP) {
> + /* AMP controllers do not support SCO packets */
> + data->isoc = NULL;
> + } else {
> + /* Interface orders are hardcoded in the specification */
> + data->isoc = usb_ifnum_to_if(data->udev, ifnum_base + 1);
> + data->isoc_ifnum = ifnum_base + 1;
> + }
> +
> #ifdef CONFIG_PM
> err = btusb_config_oob_wake(hdev);
> if (err)
> @@ -4022,6 +4047,10 @@ static int btusb_probe(struct usb_interface *intf,
> hdev->set_diag = btintel_set_diag;
> hdev->set_bdaddr = btintel_set_bdaddr;
> hdev->cmd_timeout = btusb_intel_cmd_timeout;
> +
> + if (btusb_find_altsetting(data, 6))
> + hdev->sco_mtu = hci_packet_size_usb_alt[6];
> +
> set_bit(HCI_QUIRK_STRICT_DUPLICATE_FILTER, &hdev->quirks);
> set_bit(HCI_QUIRK_SIMULTANEOUS_DISCOVERY, &hdev->quirks);
> set_bit(HCI_QUIRK_NON_PERSISTENT_DIAG, &hdev->quirks);
> @@ -4063,15 +4092,6 @@ static int btusb_probe(struct usb_interface *intf,
> btusb_check_needs_reset_resume(intf);
> }
>
> - if (id->driver_info & BTUSB_AMP) {
> - /* AMP controllers do not support SCO packets */
> - data->isoc = NULL;
> - } else {
> - /* Interface orders are hardcoded in the specification */
> - data->isoc = usb_ifnum_to_if(data->udev, ifnum_base + 1);
> - data->isoc_ifnum = ifnum_base + 1;
> - }
> -
> if (IS_ENABLED(CONFIG_BT_HCIBTUSB_RTL) &&
> (id->driver_info & BTUSB_REALTEK)) {
> hdev->setup = btrtl_setup_realtek;
> @@ -4083,9 +4103,10 @@ static int btusb_probe(struct usb_interface *intf,
> * (DEVICE_REMOTE_WAKEUP)
> */
> set_bit(BTUSB_WAKEUP_DISABLE, &data->flags);
> - if (btusb_find_altsetting(data, 1))
> + if (btusb_find_altsetting(data, 1)) {
> set_bit(BTUSB_USE_ALT1_FOR_WBS, &data->flags);
> - else
> + hdev->sco_mtu = hci_packet_size_usb_alt[1];
> + } else
> bt_dev_err(hdev, "Device does not support ALT setting 1");
> }
>
> diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
> index 33d8458fdd4adc..b3e9247fdbcfa1 100644
> --- a/net/bluetooth/hci_event.c
> +++ b/net/bluetooth/hci_event.c
> @@ -730,7 +730,12 @@ static void hci_cc_read_buffer_size(struct hci_dev *hdev, struct sk_buff *skb)
> return;
>
> hdev->acl_mtu = __le16_to_cpu(rp->acl_mtu);
> - hdev->sco_mtu = rp->sco_mtu;
> + /* Set sco_mtu only when not yet.
> + * The sco_mtu would be set in btusb.c
> + * if the host controller interface is USB.
> + */
> + if (hdev->sco_mtu == 0)
> + hdev->sco_mtu = rp->sco_mtu;
Should not hdev->sco_mtu contains minimum from the rp->sco_mtu and your
calculated value defined in hci_packet_size_usb_alt[i]?
Socket MTU cannot be bigger then value rp->sco_mtu, right?
> hdev->acl_pkts = __le16_to_cpu(rp->acl_max_pkt);
> hdev->sco_pkts = __le16_to_cpu(rp->sco_max_pkt);
>
> --
> 2.28.0.526.ge36021eeef-goog
>
