Hi Marcel,
> -----Original Message-----
> From: Marcel Holtmann <marcel@xxxxxxxxxxxx>
> Sent: Friday, July 30, 2021 7:36 PM
> To: K, Kiran <kiran.k@xxxxxxxxx>
> Cc: BlueZ <linux-bluetooth@xxxxxxxxxxxxxxx>; Srivatsa, Ravishankar
> <ravishankar.srivatsa@xxxxxxxxx>; Tumkur Narayan, Chethan
> <chethan.tumkur.narayan@xxxxxxxxx>
> Subject: Re: [PATCH v11 01/10] Bluetooth: Enumerate local supported codec
> and cache details
>
> Hi Kiran,
>
> > Move reading of supported local codecs into a separate init function,
> > query codecs capabilities and cache the data
> >
> > Signed-off-by: Kiran K <kiran.k@xxxxxxxxx>
> > Signed-off-by: Chethan T N <chethan.tumkur.narayan@xxxxxxxxx>
> > Signed-off-by: Srivatsa Ravishankar <ravishankar.srivatsa@xxxxxxxxx>
> > ---
> > * changes in v11:
> > - Remove Kconfig related changes
> > - Address minor review comments
> > - Move codec related functions to new file hci_codec.c
> >
> > * changes in v10:
> > - define Kconfig to control offload feature at build time
> > - fix review comments
> >
> > * changes in v9:
> > - use shortname vnd instead of ven
> >
> > * changes in v8:
> > - add comments
> > - split __u8 codec_id[5] into {__u8 id; __le16 cid, vid }
> > - address review comment related codec caps structure
> >
> > * changes in v7:
> > - keep codec enumeration call in hci_init instead of having a separate
> > function
> > - Remove unused bitmasks defined for LE transports
> >
> > * changes in v6:
> > - fix compiler warning reported for ARCH=arc
> >
> > * changes in v5:
> > - fix review comments
> > - move code used to read standard/vendor codecs caps into single
> > function
> >
> > * changes in v4:
> > - convert reading of codecs and codecs caps calls from async to sync
> >
> > * changes in v3
> > move codec enumeration into a new init function
> >
> > * changes in v2
> > add skb length check before accessing data
> >
> > include/net/bluetooth/hci.h | 41 +++++++
> > include/net/bluetooth/hci_core.h | 17 +++
> > net/bluetooth/Makefile | 2 +-
> > net/bluetooth/hci_codec.c | 194 +++++++++++++++++++++++++++++++
> > net/bluetooth/hci_codec.h | 6 +
> > net/bluetooth/hci_core.c | 12 +-
> > 6 files changed, 266 insertions(+), 6 deletions(-) create mode 100644
> > net/bluetooth/hci_codec.c create mode 100644 net/bluetooth/hci_codec.h
> >
> > diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
> > index b80415011dcd..f76849c8eafd 100644
> > --- a/include/net/bluetooth/hci.h
> > +++ b/include/net/bluetooth/hci.h
> > @@ -1307,6 +1307,28 @@ struct hci_rp_read_data_block_size { }
> > __packed;
> >
> > #define HCI_OP_READ_LOCAL_CODECS 0x100b
> > +struct hci_std_codecs {
> > + __u8 num;
> > + __u8 codec[];
> > +} __packed;
> > +
> > +struct hci_vnd_codec {
> > + /* company id */
> > + __le16 cid;
> > + /* vendor codec id */
> > + __le16 vid;
> > +} __packed;
> > +
> > +struct hci_vnd_codecs {
> > + __u8 num;
> > + struct hci_vnd_codec codec[];
> > +} __packed;
> > +
> > +struct hci_rp_read_local_supported_codecs {
> > + __u8 status;
> > + struct hci_std_codecs std_codecs;
> > + struct hci_vnd_codecs vnd_codecs;
> > +} __packed;
> >
> > #define HCI_OP_READ_LOCAL_PAIRING_OPTS 0x100c
> > struct hci_rp_read_local_pairing_opts { @@ -1315,6 +1337,25 @@ struct
> > hci_rp_read_local_pairing_opts {
> > __u8 max_key_size;
> > } __packed;
> >
> > +#define HCI_OP_READ_LOCAL_CODEC_CAPS 0x100e
> > +struct hci_op_read_local_codec_caps {
> > + __u8 id;
> > + __le16 cid;
> > + __le16 vid;
> > + __u8 transport;
> > + __u8 direction;
> > +} __packed;
> > +
> > +struct hci_codec_caps {
> > + __u8 len;
> > + __u8 data[];
> > +} __packed;
> > +
> > +struct hci_rp_read_local_codec_caps {
> > + __u8 status;
> > + __u8 num_caps;
> > +} __packed;
> > +
> > #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..6742e6ad7b37 100644
> > --- a/include/net/bluetooth/hci_core.h
> > +++ b/include/net/bluetooth/hci_core.h
> > @@ -131,6 +131,17 @@ struct bdaddr_list {
> > u8 bdaddr_type;
> > };
> >
> > +struct codec_list {
> > + struct list_head list;
> > + u8 id;
> > + __u16 cid;
> > + __u16 vid;
> > + u8 transport;
> > + u8 num_caps;
> > + u32 len;
> > + struct hci_codec_caps caps[];
> > +};
> > +
> > struct bdaddr_list_with_irk {
> > struct list_head list;
> > bdaddr_t bdaddr;
> > @@ -535,6 +546,7 @@ struct hci_dev {
> > struct list_head pend_le_conns;
> > struct list_head pend_le_reports;
> > struct list_head blocked_keys;
> > + struct list_head local_codecs;
> >
> > struct hci_dev_stats stat;
> >
> > @@ -1849,4 +1861,9 @@ void hci_copy_identity_address(struct hci_dev
> *hdev, bdaddr_t *bdaddr,
> > #define SCO_AIRMODE_CVSD 0x0000
> > #define SCO_AIRMODE_TRANSP 0x0003
> >
> > +#define LOCAL_CODEC_ACL_MASK BIT(0)
> > +#define LOCAL_CODEC_SCO_MASK BIT(1)
> > +
> > +#define TRANSPORT_TYPE_MAX 0x04
> > +
> > #endif /* __HCI_CORE_H */
> > diff --git a/net/bluetooth/Makefile b/net/bluetooth/Makefile index
> > cc0995301f93..f3e439d98b85 100644
> > --- a/net/bluetooth/Makefile
> > +++ b/net/bluetooth/Makefile
> > @@ -14,7 +14,7 @@ bluetooth_6lowpan-y := 6lowpan.o
> >
> > bluetooth-y := af_bluetooth.o hci_core.o hci_conn.o hci_event.o mgmt.o \
> > hci_sock.o hci_sysfs.o l2cap_core.o l2cap_sock.o smp.o lib.o \
> > - ecdh_helper.o hci_request.o mgmt_util.o mgmt_config.o
> > + ecdh_helper.o hci_request.o mgmt_util.o mgmt_config.o hci_codec.o
> >
> > bluetooth-$(CONFIG_BT_BREDR) += sco.o
> > bluetooth-$(CONFIG_BT_HS) += a2mp.o amp.o diff --git
> > a/net/bluetooth/hci_codec.c b/net/bluetooth/hci_codec.c new file mode
> > 100644 index 000000000000..205f3b04c172
> > --- /dev/null
> > +++ b/net/bluetooth/hci_codec.c
> > @@ -0,0 +1,194 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/* Copyright (C) 2021 Intel Corporation */
> > +
> > +#include <net/bluetooth/bluetooth.h>
> > +#include <net/bluetooth/hci_core.h>
> > +
> > +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;
> > +}
> > +
> > +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);
> > + }
> > + }
> > +}
>
> I said before that I don’t like it this way. The is_vnd_codec part is pointless
> and you are trickling this through. I really mean that I am not wanting to it
> this way upstream.
>
> So first of all,
>
> if (is_vnd_codec) {
> int i;
>
> for (i = 0; i < num_codecs; i++) {
> struct hci_vnd_codecs *codecs = codec_list;
> hci_read_codec_capabilities(hdev, &codecs-
> >codec[i],
> LOCAL_CODEC_ACL_MASK,
> true);
> }
> } else {
> int I;
>
> for (i = 0; i < num_codecs; i++) {
> struct hci_std_codecs *codecs = codec_list;
> hci_read_codec_capabilities(hdev, &codecs-
> >codec[i],
> LOCAL_CODEC_ACL_MASK,
> false);
> }
> }
>
> This is just by definition more efficient code. Now as caller you already know
> if you are a vendor codec list or not.
>
> static void hci_codec_list_parse_std(struct hci_dev *hdev, __u8
> num_codecs,
> struct hci_std_codecs *codecs)
> {
> int i;
>
> for (i = 0; i < num_codecs; i++)
> hci_read_codec_capabilities(hdev, &codecs-
> >codec[i],
> LOCAL_CODEC_ACL_MASK,
> false);
> }
>
> static void hci_codec_list_parse_vnd(struct hci_dev *hdev, __u8
> num_codecs,
> struct hci_vnd_codecs *codecs)
> {
> ..
> }
>
>
> This is already less code and easier to understand. Also it is type safer since
> the parameter is not a void pointer.
Ack.
>
> Now on to the LOCAL_CODEC_ACL_MASK transport setting and the
> hci_read_codec_capabilities. I have no idea why this is done this way. I can
> not follow this code since it is spaghetti left and right. This needs to be
> untangled.
>
HCI_READ_LOCAL_SUPPORTED_CODEC_CAPABILITIES command requires transport type to be specified. In HCI_READ_LOCAL_SUPPORTED_CODECS_V1, by default transport type is BREDR_ACL. Hence in this patch, caller is explicitly passing LOCAL_CODEC_ACL_MASK.
In patch 02/10, transport bit mask received in HCI_READ_LOCAL_SUPPORTED_CODECS_V2, is passed.
> I am not going to review hci_read_codec_capabilities right now, please look
> through it and come up with simpler solution.
>
> > +
> > +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);
>
>
> for (i = 0; i < std_codecs->num; i++)
> hci_read_codec_capabilities(hdev, &std_codecs->codec[i],
> LOCAL_CODEC_ACL_MASK, false);
>
> Now I am saving the function above and only need 2 extra lines. This is more
> readable since it is easier to follow.
>
> > +
> > + 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);
> > +}
> > diff --git a/net/bluetooth/hci_codec.h b/net/bluetooth/hci_codec.h new
> > file mode 100644 index 000000000000..e5e594933d07
> > --- /dev/null
> > +++ b/net/bluetooth/hci_codec.h
> > @@ -0,0 +1,6 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +
> > +/* Copyright (C) 2021 Intel Corporation */
> > +
> > +void hci_read_supported_codecs(struct hci_dev *hdev); void
> > +hci_codec_list_clear(struct list_head *codec_list);
> > diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c index
> > 2560ed2f144d..212d5066d413 100644
> > --- a/net/bluetooth/hci_core.c
> > +++ b/net/bluetooth/hci_core.c
> > @@ -45,6 +45,7 @@
> > #include "leds.h"
> > #include "msft.h"
> > #include "aosp.h"
> > +#include "hci_codec.h"
> >
> > static void hci_rx_work(struct work_struct *work); static void
> > hci_cmd_work(struct work_struct *work); @@ -838,10 +839,6 @@ 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); @@ -937,6
> > +934,10 @@ static int __hci_init(struct hci_dev *hdev)
> > if (err < 0)
> > return err;
> >
> > + /* Read local codec list if the HCI command is supported */
> > + if (hdev->commands[29] & 0x20)
> > + hci_read_supported_codecs(hdev);
> > +
> > /* 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 +1842,7 @@ 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);
> > + hci_codec_list_clear(&hdev->local_codecs);
> >
> > hci_req_sync_unlock(hdev);
> >
> > @@ -3842,7 +3844,7 @@ struct hci_dev *hci_alloc_dev(void)
> > INIT_LIST_HEAD(&hdev->conn_hash.list);
> > INIT_LIST_HEAD(&hdev->adv_instances);
> > INIT_LIST_HEAD(&hdev->blocked_keys);
> > -
> > + INIT_LIST_HEAD(&hdev->local_codecs);
> > INIT_WORK(&hdev->rx_work, hci_rx_work);
> > INIT_WORK(&hdev->cmd_work, hci_cmd_work);
> > INIT_WORK(&hdev->tx_work, hci_tx_work);
>
> This kind of style changes by removing an on purpose place empty line as
> separator are not acceptable. Please avoid them.
Ack
>
> Regards
>
> Marcel
Regards,
Kiran
