Re: [PATCH v1 2/2] Bluetooth: btintel: surface Intel telemetry events through mgmt

From: Marcel Holtmann
Date: Fri Jan 21 2022 - 15:22:02 EST


Hi Jospeh,

> When receiving a HCI vendor event, the kernel checks if it is an
> Intel telemetry event. If yes, the event is sent to bluez user
> space through the mgmt socket.
>
> Signed-off-by: Joseph Hwang <josephsih@xxxxxxxxxxxx>
> Reviewed-by: Archie Pusaka <apusaka@xxxxxxxxxxxx>
> ---
>
> drivers/bluetooth/btintel.c | 43 +++++++++++++++++++++++++++++++-
> drivers/bluetooth/btintel.h | 12 +++++++++
> include/net/bluetooth/hci_core.h | 2 ++
> net/bluetooth/hci_event.c | 12 ++++++---
> 4 files changed, 65 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/bluetooth/btintel.c b/drivers/bluetooth/btintel.c
> index 1a4f8b227eac..d3b7a796cb91 100644
> --- a/drivers/bluetooth/btintel.c
> +++ b/drivers/bluetooth/btintel.c
> @@ -2401,8 +2401,10 @@ static int btintel_setup_combined(struct hci_dev *hdev)
> set_bit(HCI_QUIRK_SIMULTANEOUS_DISCOVERY, &hdev->quirks);
> set_bit(HCI_QUIRK_NON_PERSISTENT_DIAG, &hdev->quirks);
>
> - /* Set up the quality report callback for Intel devices */
> + /* Set up the quality report callbacks for Intel devices */
> hdev->set_quality_report = btintel_set_quality_report;
> + hdev->is_quality_report_evt = btintel_is_quality_report_evt;
> + hdev->pull_quality_report_data = btintel_pull_quality_report_data;

we are not doing this. This is all internal handling. Don’t bother the core hci_dev with it.

>
> /* For Legacy device, check the HW platform value and size */
> if (skb->len == sizeof(ver) && skb->data[1] == 0x37) {
> @@ -2645,6 +2647,45 @@ void btintel_secure_send_result(struct hci_dev *hdev,
> }
> EXPORT_SYMBOL_GPL(btintel_secure_send_result);
>
> +#define INTEL_PREFIX 0x8087
> +#define TELEMETRY_CODE 0x03
> +
> +struct intel_prefix_evt_data {
> + __le16 vendor_prefix;
> + __u8 code;
> + __u8 data[0]; /* a number of struct intel_tlv subevents */
> +} __packed;
> +
> +bool btintel_is_quality_report_evt(struct sk_buff *skb)
> +{
> + struct intel_prefix_evt_data *ev;
> + u16 vendor_prefix;
> +
> + if (skb->len < sizeof(struct intel_prefix_evt_data))
> + return false;
> +
> + ev = (struct intel_prefix_evt_data *)skb->data;
> + vendor_prefix = __le16_to_cpu(ev->vendor_prefix);
> +
> + return vendor_prefix == INTEL_PREFIX && ev->code == TELEMETRY_CODE;
> +}
> +EXPORT_SYMBOL_GPL(btintel_is_quality_report_evt);
> +
> +bool btintel_pull_quality_report_data(struct sk_buff *skb)
> +{
> + skb_pull(skb, sizeof(struct intel_prefix_evt_data));
> +
> + /* A telemetry event contains at least one intel_tlv subevent. */
> + if (skb->len < sizeof(struct intel_tlv)) {
> + BT_ERR("Telemetry event length %d too short (at least %u)",
> + skb->len, sizeof(struct intel_tlv));
> + return false;
> + }
> +
> + return true;
> +}
> +EXPORT_SYMBOL_GPL(btintel_pull_quality_report_data);
> +
> MODULE_AUTHOR("Marcel Holtmann <marcel@xxxxxxxxxxxx>");
> MODULE_DESCRIPTION("Bluetooth support for Intel devices ver " VERSION);
> MODULE_VERSION(VERSION);
> diff --git a/drivers/bluetooth/btintel.h b/drivers/bluetooth/btintel.h
> index c9b24e9299e2..841aef3dbd4c 100644
> --- a/drivers/bluetooth/btintel.h
> +++ b/drivers/bluetooth/btintel.h
> @@ -210,6 +210,8 @@ void btintel_bootup(struct hci_dev *hdev, const void *ptr, unsigned int len);
> void btintel_secure_send_result(struct hci_dev *hdev,
> const void *ptr, unsigned int len);
> int btintel_set_quality_report(struct hci_dev *hdev, bool enable);
> +bool btintel_is_quality_report_evt(struct sk_buff *skb);
> +bool btintel_pull_quality_report_data(struct sk_buff *skb);
> #else
>
> static inline int btintel_check_bdaddr(struct hci_dev *hdev)
> @@ -305,4 +307,14 @@ static inline int btintel_set_quality_report(struct hci_dev *hdev, bool enable)
> {
> return -ENODEV;
> }
> +
> +static inline bool btintel_is_quality_report_evt(struct sk_buff *skb)
> +{
> + return false;
> +}
> +
> +static inline bool btintel_pull_quality_report_data(struct sk_buff *skb);
> +{
> + return false;
> +}
> #endif
> diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
> index 727cb9c056b2..b74ba1585df9 100644
> --- a/include/net/bluetooth/hci_core.h
> +++ b/include/net/bluetooth/hci_core.h
> @@ -632,6 +632,8 @@ struct hci_dev {
> void (*cmd_timeout)(struct hci_dev *hdev);
> bool (*wakeup)(struct hci_dev *hdev);
> int (*set_quality_report)(struct hci_dev *hdev, bool enable);
> + bool (*is_quality_report_evt)(struct sk_buff *skb);
> + bool (*pull_quality_report_data)(struct sk_buff *skb);
> int (*get_data_path_id)(struct hci_dev *hdev, __u8 *data_path);
> int (*get_codec_config_data)(struct hci_dev *hdev, __u8 type,
> struct bt_codec *codec, __u8 *vnd_len,
> diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
> index bccb659a9454..5f9cc7b942a1 100644
> --- a/net/bluetooth/hci_event.c
> +++ b/net/bluetooth/hci_event.c
> @@ -4237,11 +4237,17 @@ static bool quality_report_evt(struct hci_dev *hdev, void *data,
> if (aosp_has_quality_report(hdev) &&
> aosp_pull_quality_report_data(skb))
> mgmt_quality_report(hdev, skb, QUALITY_SPEC_AOSP_BQR);
> -
> - return true;
> + } else if (hdev->is_quality_report_evt &&
> + hdev->is_quality_report_evt(skb)) {
> + if (hdev->set_quality_report &&
> + hdev->pull_quality_report_data(skb))
> + mgmt_quality_report(hdev, skb,
> + QUALITY_SPEC_INTEL_TELEMETRY);
> + } else {
> + return false;
> }

No. You now have Intel internal details bleeding into the core.

Regards

Marcel