Re: [PATCH v7 4/4] Bluetooth: Support the quality report events

From: Luiz Augusto von Dentz
Date: Thu Aug 12 2021 - 14:07:07 EST


Hi Joseph,

On Thu, Aug 12, 2021 at 2:16 AM Joseph Hwang <josephsih@xxxxxxxxxxxx> wrote:
>
> This patch allows a user space process to enable/disable the quality
> report events dynamically through the set experimental feature mgmt
> interface if CONFIG_BT_FEATURE_QUALITY_REPORT is enabled.
>
> Since the quality report feature needs to invoke the callback function
> provided by the driver, i.e., hdev->set_quality_report, a valid
> controller index is required.
>
> Reviewed-by: Miao-chen Chou <mcchou@xxxxxxxxxxxx>
> Signed-off-by: Joseph Hwang <josephsih@xxxxxxxxxxxx>
> ---
>
> Changes in v7:
> - Rebase on Tedd's patches that moved functionality from btusb to
> btintel.
>
> Changes in v5:
> - Removed CONFIG_BT_FEATURE_QUALITY_REPORT since there was no
> large size impact.
>
> include/net/bluetooth/hci.h | 1 +
> include/net/bluetooth/hci_core.h | 2 +
> net/bluetooth/mgmt.c | 110 ++++++++++++++++++++++++++++++-
> 3 files changed, 112 insertions(+), 1 deletion(-)
>
> diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
> index b80415011dcd..bb6b7398f490 100644
> --- a/include/net/bluetooth/hci.h
> +++ b/include/net/bluetooth/hci.h
> @@ -330,6 +330,7 @@ enum {
> HCI_ENABLE_LL_PRIVACY,
> HCI_CMD_PENDING,
> HCI_FORCE_NO_MITM,
> + HCI_QUALITY_REPORT,

Hmm, 3/4 actually makes use of HCI_QUALITY_REPORT so this should
actually appear before it (3/4 4/4 should be swapped) otherwise we
break the likes of bisect, I usually recommend using git rebase -i
origin/master --exec make to check if each and every change build
properly.

>
> __HCI_NUM_FLAGS,
> };
> diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
> index a7d06d7da602..7e9ae36b2582 100644
> --- a/include/net/bluetooth/hci_core.h
> +++ b/include/net/bluetooth/hci_core.h
> @@ -606,6 +606,7 @@ struct hci_dev {
> int (*set_bdaddr)(struct hci_dev *hdev, const bdaddr_t *bdaddr);
> void (*cmd_timeout)(struct hci_dev *hdev);
> bool (*prevent_wake)(struct hci_dev *hdev);
> + int (*set_quality_report)(struct hci_dev *hdev, bool enable);
> };
>
> #define HCI_PHY_HANDLE(handle) (handle & 0xff)
> @@ -759,6 +760,7 @@ extern struct mutex hci_cb_list_lock;
> hci_dev_clear_flag(hdev, HCI_LE_ADV); \
> hci_dev_clear_flag(hdev, HCI_LL_RPA_RESOLUTION);\
> hci_dev_clear_flag(hdev, HCI_PERIODIC_INQ); \
> + hci_dev_clear_flag(hdev, HCI_QUALITY_REPORT); \
> } while (0)
>
> /* ----- HCI interface to upper protocols ----- */
> diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
> index 1e21e014efd2..358250862720 100644
> --- a/net/bluetooth/mgmt.c
> +++ b/net/bluetooth/mgmt.c
> @@ -3791,6 +3791,12 @@ static const u8 debug_uuid[16] = {
> };
> #endif
>
> +/* 330859bc-7506-492d-9370-9a6f0614037f */
> +static const u8 quality_report_uuid[16] = {
> + 0x7f, 0x03, 0x14, 0x06, 0x6f, 0x9a, 0x70, 0x93,
> + 0x2d, 0x49, 0x06, 0x75, 0xbc, 0x59, 0x08, 0x33,
> +};
> +
> /* 671b10b5-42c0-4696-9227-eb28d1b049d6 */
> static const u8 simult_central_periph_uuid[16] = {
> 0xd6, 0x49, 0xb0, 0xd1, 0x28, 0xeb, 0x27, 0x92,
> @@ -3806,7 +3812,7 @@ static const u8 rpa_resolution_uuid[16] = {
> static int read_exp_features_info(struct sock *sk, struct hci_dev *hdev,
> void *data, u16 data_len)
> {
> - char buf[62]; /* Enough space for 3 features */
> + char buf[82]; /* Enough space for 4 features: 2 + 20 * 4 */
> struct mgmt_rp_read_exp_features_info *rp = (void *)buf;
> u16 idx = 0;
> u32 flags;
> @@ -3850,6 +3856,24 @@ static int read_exp_features_info(struct sock *sk, struct hci_dev *hdev,
> idx++;
> }
>
> + if (hdev) {
> + if (hdev->set_quality_report) {
> + /* BIT(0): indicating if set_quality_report is
> + * supported by controller.
> + */
> + flags = BIT(0);
> +
> + /* BIT(1): indicating if the feature is enabled. */
> + if (hci_dev_test_flag(hdev, HCI_QUALITY_REPORT))
> + flags |= BIT(1);
> + } else {
> + flags = 0;
> + }
> + memcpy(rp->features[idx].uuid, quality_report_uuid, 16);
> + rp->features[idx].flags = cpu_to_le32(flags);
> + idx++;
> + }
> +
> rp->feature_count = cpu_to_le16(idx);
>
> /* After reading the experimental features information, enable
> @@ -3892,6 +3916,21 @@ static int exp_debug_feature_changed(bool enabled, struct sock *skip)
> }
> #endif
>
> +static int exp_quality_report_feature_changed(bool enabled, struct sock *skip)
> +{
> + struct mgmt_ev_exp_feature_changed ev;
> +
> + BT_INFO("enabled %d", enabled);
> +
> + memset(&ev, 0, sizeof(ev));
> + memcpy(ev.uuid, quality_report_uuid, 16);
> + ev.flags = cpu_to_le32(enabled ? BIT(0) : 0);
> +
> + return mgmt_limited_event(MGMT_EV_EXP_FEATURE_CHANGED, NULL,
> + &ev, sizeof(ev),
> + HCI_MGMT_EXP_FEATURE_EVENTS, skip);
> +}
> +
> static int set_exp_feature(struct sock *sk, struct hci_dev *hdev,
> void *data, u16 data_len)
> {
> @@ -4038,6 +4077,75 @@ static int set_exp_feature(struct sock *sk, struct hci_dev *hdev,
> return err;
> }

Perhaps it would be a good idea to have a function table e.g:

struct mgmt_exp_feature {
const char *uuid;
int (func*)(...)
} exp_features[] = {
...
};

That way we don't have to add such changes directly into
set_exp_feature just in the table and implement its callback.

> + if (!memcmp(cp->uuid, quality_report_uuid, 16)) {
> + bool val, changed;
> + int err;
> +
> + /* Command requires to use a valid controller index */
> + if (!hdev)
> + return mgmt_cmd_status(sk, MGMT_INDEX_NONE,
> + MGMT_OP_SET_EXP_FEATURE,
> + MGMT_STATUS_INVALID_INDEX);
> +
> + /* Parameters are limited to a single octet */
> + if (data_len != MGMT_SET_EXP_FEATURE_SIZE + 1)
> + return mgmt_cmd_status(sk, hdev->id,
> + MGMT_OP_SET_EXP_FEATURE,
> + MGMT_STATUS_INVALID_PARAMS);
> +
> + /* Only boolean on/off is supported */
> + if (cp->param[0] != 0x00 && cp->param[0] != 0x01)
> + return mgmt_cmd_status(sk, hdev->id,
> + MGMT_OP_SET_EXP_FEATURE,
> + MGMT_STATUS_INVALID_PARAMS);
> +
> + hci_req_sync_lock(hdev);
> +
> + val = !!cp->param[0];
> + changed = (val != hci_dev_test_flag(hdev, HCI_QUALITY_REPORT));
> +
> + if (!hdev->set_quality_report) {
> + BT_INFO("quality report not supported");
> + err = mgmt_cmd_status(sk, hdev->id,
> + MGMT_OP_SET_EXP_FEATURE,
> + MGMT_STATUS_NOT_SUPPORTED);
> + goto unlock_quality_report;
> + }
> +
> + if (changed) {
> + err = hdev->set_quality_report(hdev, val);
> + if (err) {
> + BT_ERR("set_quality_report value %d err %d",
> + val, err);
> + err = mgmt_cmd_status(sk, hdev->id,
> + MGMT_OP_SET_EXP_FEATURE,
> + MGMT_STATUS_FAILED);
> + goto unlock_quality_report;
> + }
> + if (val)
> + hci_dev_set_flag(hdev, HCI_QUALITY_REPORT);
> + else
> + hci_dev_clear_flag(hdev, HCI_QUALITY_REPORT);
> + }
> +
> + BT_INFO("quality report enable %d changed %d",
> + val, changed);
> +
> + memcpy(rp.uuid, quality_report_uuid, 16);
> + rp.flags = cpu_to_le32(val ? BIT(0) : 0);
> + hci_sock_set_flag(sk, HCI_MGMT_EXP_FEATURE_EVENTS);
> + err = mgmt_cmd_complete(sk, hdev->id,
> + MGMT_OP_SET_EXP_FEATURE, 0,
> + &rp, sizeof(rp));
> +
> + if (changed)
> + exp_quality_report_feature_changed(val, sk);
> +
> +unlock_quality_report:
> + hci_req_sync_unlock(hdev);
> + return err;
> + }
> +
> return mgmt_cmd_status(sk, hdev ? hdev->id : MGMT_INDEX_NONE,
> MGMT_OP_SET_EXP_FEATURE,
> MGMT_STATUS_NOT_SUPPORTED);
> --
> 2.32.0.605.g8dce9f2422-goog
>


--
Luiz Augusto von Dentz