RE: [PATCH v10 01/10] Bluetooth: Enumerate local supported codec and cache details

["K, Kiran" <kiran.k@intel.com>]

Hi Luiz,

> >  #define HCI_OP_READ_PAGE_SCAN_ACTIVITY 0x0c1b  struct
> > hci_rp_read_page_scan_activity {
> >         __u8     status;
> > diff --git a/include/net/bluetooth/hci_core.h
> > b/include/net/bluetooth/hci_core.h
> > index a53e94459ecd..7b8d603358b9 100644
> > --- a/include/net/bluetooth/hci_core.h
> > +++ b/include/net/bluetooth/hci_core.h
> > @@ -131,6 +131,19 @@ struct bdaddr_list {
> >         u8 bdaddr_type;
> >  };
> >
> > +#if IS_ENABLED(CONFIG_BT_OFFLOAD_CODECS)
> > +struct codec_list {
> > +       struct list_head list;
> > +       u8      id;
> > +       __le16  cid;
> > +       __le16  vid;
> 
> I wonder why you are not storing these fields in host byte order?
> Looks odd since everything else is using host order.

Ack. I will change this to host order.
> 
> > +       u8      transport;
> > +       u8      num_caps;
> > +       u32     len;
> > +       struct hci_codec_caps caps[];
> > +};
> > +#endif
> > +
> >  struct bdaddr_list_with_irk {
> >         struct list_head list;
> >         bdaddr_t bdaddr;
> > @@ -535,6 +548,9 @@ struct hci_dev {
> >         struct list_head        pend_le_conns;
> >         struct list_head        pend_le_reports;
> >         struct list_head        blocked_keys;
> > +#if IS_ENABLED(CONFIG_BT_OFFLOAD_CODECS)
> > +       struct list_head        local_codecs;
> > +#endif
> 
> I wonder if this is preferable over just leaving the local_codecs empty as we
> would probably just save a couple of bytes here but when using
> preprocessor #if that means we can no longer use IS_ENABLED directly inside
> the C statements.
Ack. 
> 
> >
> >         struct hci_dev_stats    stat;
> >
> > @@ -1849,4 +1865,11 @@ void hci_copy_identity_address(struct hci_dev
> *hdev, bdaddr_t *bdaddr,
> >  #define SCO_AIRMODE_CVSD       0x0000
> >  #define SCO_AIRMODE_TRANSP     0x0003
> >
> > +#if IS_ENABLED(CONFIG_BT_OFFLOAD_CODECS)
> > +#define LOCAL_CODEC_ACL_MASK   BIT(0)
> > +#define LOCAL_CODEC_SCO_MASK   BIT(1)
> > +
> > +#define TRANSPORT_TYPE_MAX     0x04
> 
> Ditto, Id just have these defines all the time.

Ack

> 
> > +#endif
> > +
> >  #endif /* __HCI_CORE_H */
> > diff --git a/net/bluetooth/Kconfig b/net/bluetooth/Kconfig index
> > e0ab4cd7afc3..1069623f36c4 100644
> > --- a/net/bluetooth/Kconfig
> > +++ b/net/bluetooth/Kconfig
> > @@ -92,6 +92,17 @@ config BT_LEDS
> >           This option selects a few LED triggers for different
> >           Bluetooth events.
> >
> > +config BT_OFFLOAD_CODECS
> > +       bool "Enable offload codecs"
> > +       depends on BT && BT_BREDR
> > +       default n
> > +       help
> > +         This option enables offload codecs if controller supports.
> > +         When this option is enabled, user space audio modules can
> > +         query offload codecs and can set the codec to be used for
> > +         specific use case.
> 
> I would have named this BT_HCI_CODECS.

I believe in 10/10 patch, Marcel and you agreed to not to have Kconfig altogether.

> 
> > +
> >  config BT_MSFTEXT
> >         bool "Enable Microsoft extensions"
> >         depends on BT
> > diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index
> > 2560ed2f144d..2657d84e8240 100644
> > --- a/net/bluetooth/hci_core.c
> > +++ b/net/bluetooth/hci_core.c
> > @@ -838,10 +838,6 @@ static int hci_init4_req(struct hci_request *req,
> unsigned long opt)
> >         if (hdev->commands[22] & 0x04)
> >                 hci_set_event_mask_page_2(req);
> >
> > -       /* Read local codec list if the HCI command is supported */
> > -       if (hdev->commands[29] & 0x20)
> > -               hci_req_add(req, HCI_OP_READ_LOCAL_CODECS, 0, NULL);
> > -
> >         /* Read local pairing options if the HCI command is supported */
> >         if (hdev->commands[41] & 0x08)
> >                 hci_req_add(req, HCI_OP_READ_LOCAL_PAIRING_OPTS, 0,
> > NULL); @@ -907,6 +903,197 @@ static int hci_init4_req(struct hci_request
> *req, unsigned long opt)
> >         return 0;
> >  }
> >
> > +#if IS_ENABLED(CONFIG_BT_OFFLOAD_CODECS)
> > +static int hci_codec_list_add(struct list_head *list,
> > +                             struct hci_op_read_local_codec_caps *sent,
> > +                             struct hci_rp_read_local_codec_caps *rp,
> > +                             void *caps,
> > +                             __u32 len) {
> > +       struct codec_list *entry;
> > +
> > +       entry = kzalloc(sizeof(*entry) + len, GFP_KERNEL);
> > +       if (!entry)
> > +               return -ENOMEM;
> > +
> > +       entry->id = sent->id;
> > +       if (sent->id == 0xFF) {
> > +               entry->cid = __le16_to_cpu(sent->cid);
> > +               entry->vid = __le16_to_cpu(sent->vid);
> > +       }
> > +       entry->transport = sent->transport;
> > +       entry->len = len;
> > +       entry->num_caps = rp->num_caps;
> > +       if (rp->num_caps)
> > +               memcpy(entry->caps, caps, len);
> > +       list_add(&entry->list, list);
> > +
> > +       return 0;
> > +}
> > +
> > +static void hci_codec_list_clear(struct list_head *codec_list) {
> > +       struct codec_list *c, *n;
> > +
> > +       list_for_each_entry_safe(c, n, codec_list, list) {
> > +               list_del(&c->list);
> > +               kfree(c);
> > +       }
> > +}
> > +
> > +static void hci_read_codec_capabilities(struct hci_dev *hdev, void
> *codec_id,
> > +                                       __u8 transport, bool
> > +is_vnd_codec) {
> > +       struct hci_op_read_local_codec_caps cmd;
> > +       __u8 i;
> > +
> > +       memset(&cmd, 0, sizeof(cmd));
> > +
> > +       if (is_vnd_codec) {
> > +               struct hci_vnd_codec *vnd_codec;
> > +
> > +               vnd_codec = codec_id;
> > +               cmd.id = 0xFF;
> > +               cmd.cid = vnd_codec->cid;
> > +               cmd.vid = vnd_codec->vid;
> > +       } else {
> > +               cmd.id = *(__u8 *)codec_id;
> > +       }
> > +
> > +       cmd.direction = 0x00;
> > +
> > +       for (i = 0; i < TRANSPORT_TYPE_MAX; i++) {
> > +               if (transport & BIT(i)) {
> > +                       struct hci_rp_read_local_codec_caps *rp;
> > +                       struct hci_codec_caps *caps;
> > +                       struct sk_buff *skb;
> > +                       __u8 j;
> > +                       __u32 len;
> > +
> > +                       cmd.transport = i;
> > +                       skb = __hci_cmd_sync(hdev,
> HCI_OP_READ_LOCAL_CODEC_CAPS,
> > +                                            sizeof(cmd), &cmd,
> > +                                            HCI_CMD_TIMEOUT);
> > +                       if (IS_ERR(skb)) {
> > +                               bt_dev_err(hdev, "Failed to read codec capabilities
> (%ld)",
> > +                                          PTR_ERR(skb));
> > +                               continue;
> > +                       }
> > +
> > +                       if (skb->len < sizeof(*rp))
> > +                               goto error;
> > +
> > +                       rp = (void *)skb->data;
> > +
> > +                       if (rp->status)
> > +                               goto error;
> > +
> > +                       if (!rp->num_caps) {
> > +                               len = 0;
> > +                               /* this codec doesn't have capabilities */
> > +                               goto skip_caps_parse;
> > +                       }
> > +
> > +                       skb_pull(skb, sizeof(*rp));
> > +
> > +                       for (j = 0, len = 0; j < rp->num_caps; j++) {
> > +                               caps = (void *)skb->data;
> > +                               if (skb->len < sizeof(*caps))
> > +                                       goto error;
> > +                               if (skb->len < caps->len)
> > +                                       goto error;
> > +                               len += sizeof(caps->len) + caps->len;
> > +                               skb_pull(skb,  sizeof(caps->len) + caps->len);
> > +                       }
> > +
> > +skip_caps_parse:
> > +                       hci_dev_lock(hdev);
> > +                       hci_codec_list_add(&hdev->local_codecs, &cmd, rp,
> > +                                          (__u8 *)rp + sizeof(*rp), len);
> > +                       hci_dev_unlock(hdev);
> > +error:
> > +                       kfree_skb(skb);
> > +               }
> > +       }
> > +}
> > +
> > +static void hci_codec_list_parse(struct hci_dev *hdev, __u8 num_codecs,
> > +                                void *codec_list, bool is_vnd_codec)
> > +{
> > +       __u8 i;
> > +
> > +       for (i = 0; i < num_codecs; i++) {
> > +               if (!is_vnd_codec) {
> > +                       struct hci_std_codecs *codecs = codec_list;
> > +
> > +                       hci_read_codec_capabilities(hdev, &codecs->codec[i],
> > +                                                   LOCAL_CODEC_ACL_MASK,
> > +                                                   is_vnd_codec);
> > +               } else {
> > +                       struct hci_vnd_codecs *codecs = codec_list;
> > +
> > +                       hci_read_codec_capabilities(hdev, &codecs->codec[i],
> > +                                                   LOCAL_CODEC_ACL_MASK,
> > +                                                   is_vnd_codec);
> > +               }
> > +       }
> > +}
> > +
> > +static void hci_read_supported_codecs(struct hci_dev *hdev) {
> > +       struct sk_buff *skb;
> > +       struct hci_rp_read_local_supported_codecs *rp;
> > +       struct hci_std_codecs *std_codecs;
> > +       struct hci_vnd_codecs *vnd_codecs;
> > +
> > +       skb = __hci_cmd_sync(hdev, HCI_OP_READ_LOCAL_CODECS, 0, NULL,
> > +                            HCI_CMD_TIMEOUT);
> > +
> > +       if (IS_ERR(skb)) {
> > +               bt_dev_err(hdev, "Failed to read local supported codecs (%ld)",
> > +                          PTR_ERR(skb));
> > +               return;
> > +       }
> > +
> > +       if (skb->len < sizeof(*rp))
> > +               goto error;
> > +
> > +       rp = (void *)skb->data;
> > +
> > +       if (rp->status)
> > +               goto error;
> > +
> > +       skb_pull(skb, sizeof(rp->status));
> > +
> > +       std_codecs = (void *)skb->data;
> > +
> > +       /* validate codecs length before accessing */
> > +       if (skb->len < flex_array_size(std_codecs, codec, std_codecs->num)
> > +           + sizeof(std_codecs->num))
> > +               goto error;
> > +
> > +       /* enumerate codec capabilities of standard codecs */
> > +       hci_codec_list_parse(hdev, std_codecs->num, std_codecs,
> > + false);
> > +
> > +       skb_pull(skb, flex_array_size(std_codecs, codec, std_codecs->num)
> > +                + sizeof(std_codecs->num));
> > +
> > +       vnd_codecs = (void *)skb->data;
> > +
> > +       /* validate vendor codecs length before accessing */
> > +       if (skb->len <
> > +           flex_array_size(vnd_codecs, codec, vnd_codecs->num)
> > +           + sizeof(vnd_codecs->num))
> > +               goto error;
> > +
> > +       /* enumerate vendor codec capabilities */
> > +       hci_codec_list_parse(hdev, vnd_codecs->num, vnd_codecs, true);
> > +
> > +error:
> > +       kfree_skb(skb);
> > +}
> > +#endif
> 
> We might as well move these to hci_codec.c so we just enable/disable via
> Makefile, hci_core.c is getting a little too convoluted handling so many things.
> 
> >  static int __hci_init(struct hci_dev *hdev)  {
> >         int err;
> > @@ -937,6 +1124,12 @@ static int __hci_init(struct hci_dev *hdev)
> >         if (err < 0)
> >                 return err;
> >
> > +#if IS_ENABLED(CONFIG_BT_OFFLOAD_CODECS)
> > +       /* Read local codec list if the HCI command is supported */
> > +       if (hdev->commands[29] & 0x20)
> > +               hci_read_supported_codecs(hdev); #endif
> > +
> >         /* This function is only called when the controller is actually in
> >          * configured state. When the controller is marked as unconfigured,
> >          * this initialization procedure is not run.
> > @@ -1841,6 +2034,9 @@ int hci_dev_do_close(struct hci_dev *hdev)
> >         memset(hdev->eir, 0, sizeof(hdev->eir));
> >         memset(hdev->dev_class, 0, sizeof(hdev->dev_class));
> >         bacpy(&hdev->random_addr, BDADDR_ANY);
> > +#if IS_ENABLED(CONFIG_BT_OFFLOAD_CODECS)
> > +       hci_codec_list_clear(&hdev->local_codecs);
> > +#endif
> >
> >         hci_req_sync_unlock(hdev);
> >
> > @@ -3843,6 +4039,9 @@ struct hci_dev *hci_alloc_dev(void)
> >         INIT_LIST_HEAD(&hdev->adv_instances);
> >         INIT_LIST_HEAD(&hdev->blocked_keys);
> >
> > +#if IS_ENABLED(CONFIG_BT_OFFLOAD_CODECS)
> > +       INIT_LIST_HEAD(&hdev->local_codecs);
> > +#endif
> >         INIT_WORK(&hdev->rx_work, hci_rx_work);
> >         INIT_WORK(&hdev->cmd_work, hci_cmd_work);
> >         INIT_WORK(&hdev->tx_work, hci_tx_work);
> > --
> > 2.17.1
> >
> 
> 
> --
> Luiz Augusto von Dentz

Thanks,
Kiran