Hi Sonny,
On Sat, Dec 12, 2020 at 9:57 PM Sonny Sasaka <sonnysasaka@xxxxxxxxxxxx> wrote:
>
> To optimize BLE HID devices reconnection response, we can cache the
> report map so that the subsequent reconnections do not need round trip
> time to read the report map.
>
> Reviewed-by: Alain Michaud <alainm@xxxxxxxxxxxx>
>
> ---
> profiles/input/hog-lib.c | 142 ++++++++++++++++++++++++++++++++-------
> 1 file changed, 118 insertions(+), 24 deletions(-)
>
> diff --git a/profiles/input/hog-lib.c b/profiles/input/hog-lib.c
> index ee811d301..e5fef4c7c 100644
> --- a/profiles/input/hog-lib.c
> +++ b/profiles/input/hog-lib.c
> @@ -95,6 +95,13 @@ struct bt_hog {
> struct queue *bas;
> GSList *instances;
> struct queue *gatt_op;
> + struct gatt_db *gatt_db;
> + struct gatt_db_attribute *report_map_attr;
> +};
> +
> +struct report_map {
> + uint8_t value[HOG_REPORT_MAP_MAX_SIZE];
> + size_t length;
> };
>
> struct report {
> @@ -924,33 +931,16 @@ static char *item2string(char *str, uint8_t *buf, uint8_t len)
> return str;
> }
>
> -static void report_map_read_cb(guint8 status, const guint8 *pdu, guint16 plen,
> - gpointer user_data)
> +static void uhid_create(struct bt_hog *hog, uint8_t *report_map,
> + ssize_t report_map_len)
> {
> - struct gatt_request *req = user_data;
> - struct bt_hog *hog = req->user_data;
> - uint8_t value[HOG_REPORT_MAP_MAX_SIZE];
> + uint8_t *value = report_map;
> struct uhid_event ev;
> - ssize_t vlen;
> + ssize_t vlen = report_map_len;
> char itemstr[20]; /* 5x3 (data) + 4 (continuation) + 1 (null) */
> int i, err;
> GError *gerr = NULL;
>
> - destroy_gatt_req(req);
> -
> - DBG("HoG inspecting report map");
> -
> - if (status != 0) {
> - error("Report Map read failed: %s", att_ecode2str(status));
> - return;
> - }
> -
> - vlen = dec_read_resp(pdu, plen, value, sizeof(value));
> - if (vlen < 0) {
> - error("ATT protocol error");
> - return;
> - }
> -
> DBG("Report MAP:");
> for (i = 0; i < vlen;) {
> ssize_t ilen = 0;
> @@ -1022,6 +1012,43 @@ static void report_map_read_cb(guint8 status, const guint8 *pdu, guint16 plen,
> DBG("HoG created uHID device");
> }
>
> +static void db_report_map_write_value_cb(struct gatt_db_attribute *attr,
> + int err, void *user_data)
> +{
> + if (err)
> + error("Error writing report map value to gatt db");
> +}
> +
> +static void report_map_read_cb(guint8 status, const guint8 *pdu, guint16 plen,
> + gpointer user_data)
> +{
> + struct gatt_request *req = user_data;
> + struct bt_hog *hog = req->user_data;
> + uint8_t value[HOG_REPORT_MAP_MAX_SIZE];
> + ssize_t vlen;
> +
> + destroy_gatt_req(req);
> +
> + DBG("HoG inspecting report map");
> +
> + if (status != 0) {
> + error("Report Map read failed: %s", att_ecode2str(status));
> + return;
> + }
> +
> + vlen = dec_read_resp(pdu, plen, value, sizeof(value));
> + if (vlen < 0) {
> + error("ATT protocol error");
> + return;
> + }
> +
> + uhid_create(hog, value, vlen);
> +
> + /* Cache the report map to optimize reconnection */
> + gatt_db_attribute_write(hog->report_map_attr, 0, value, vlen, 0, NULL,
> + db_report_map_write_value_cb, NULL);
> +}
> +
> static void info_read_cb(guint8 status, const guint8 *pdu, guint16 plen,
> gpointer user_data)
> {
> @@ -1269,12 +1296,32 @@ static void foreach_hog_external(struct gatt_db_attribute *attr,
> external_report_reference_cb, hog);
> }
>
> +static void db_report_map_read_value_cb(struct gatt_db_attribute *attrib,
> + int err, const uint8_t *value,
> + size_t length, void *user_data)
> +{
> + struct report_map *map = user_data;
> +
> + if (err) {
> + error("Error reading report map from gatt db %s",
> + strerror(-err));
> + return;
> + }
> +
> + if (!length)
> + return;
> +
> + map->length = length < sizeof(map->value) ? length : sizeof(map->value);
> + memcpy(map->value, value, map->length);
> +}
> +
> static void foreach_hog_chrc(struct gatt_db_attribute *attr, void *user_data)
> {
> struct bt_hog *hog = user_data;
> bt_uuid_t uuid, report_uuid, report_map_uuid, info_uuid;
> bt_uuid_t proto_mode_uuid, ctrlpt_uuid;
> uint16_t handle, value_handle;
> + struct report_map report_map = {0};
>
> gatt_db_attribute_get_char_data(attr, &handle, &value_handle, NULL,
> NULL, &uuid);
> @@ -1288,8 +1335,24 @@ static void foreach_hog_chrc(struct gatt_db_attribute *attr, void *user_data)
>
> bt_uuid16_create(&report_map_uuid, HOG_REPORT_MAP_UUID);
> if (!bt_uuid_cmp(&report_map_uuid, &uuid)) {
> - read_char(hog, hog->attrib, value_handle, report_map_read_cb,
> - hog);
> +
> + hog->report_map_attr = gatt_db_get_attribute(hog->gatt_db,
> + value_handle);
> + gatt_db_attribute_read(hog->report_map_attr, 0,
> + BT_ATT_OP_READ_REQ, NULL,
> + db_report_map_read_value_cb,
> + &report_map);
> +
> + if (report_map.length) {
> + /* Report map found in the cache, straight to creating
> + * UHID to optimize reconnection.
> + */
> + uhid_create(hog, report_map.value, report_map.length);
> + } else {
> + read_char(hog, hog->attrib, value_handle,
> + report_map_read_cb, hog);
> + }
> +
> gatt_db_service_foreach_desc(attr, foreach_hog_external, hog);
> return;
> }
> @@ -1417,6 +1480,8 @@ struct bt_hog *bt_hog_new(int fd, const char *name, uint16_t vendor,
> hog->dis = bt_dis_new(db);
> bt_dis_set_notification(hog->dis, dis_notify, hog);
> }
> +
> + hog->gatt_db = db;
Is this really supposed to be a weak reference?
> }
>
> return bt_hog_ref(hog);
> @@ -1612,9 +1677,14 @@ bool bt_hog_attach(struct bt_hog *hog, void *gatt)
> hog->primary->range.start,
> hog->primary->range.end, NULL,
> char_discovered_cb, hog);
> - return true;
> }
>
> + if (!hog->uhid_created)
> + return true;
> +
> + /* If UHID is already created, set up the report value handlers to
> + * optimize reconnection.
> + */
> for (l = hog->reports; l; l = l->next) {
> struct report *r = l->data;
>
> @@ -1627,6 +1697,29 @@ bool bt_hog_attach(struct bt_hog *hog, void *gatt)
> return true;
> }
>
> +static void uhid_destroy(struct bt_hog *hog)
> +{
> + int err;
> + struct uhid_event ev;
> +
> + if (!hog->uhid_created)
> + return;
> +
> + bt_uhid_unregister_all(hog->uhid);
> +
> + memset(&ev, 0, sizeof(ev));
> + ev.type = UHID_DESTROY;
> +
> + err = bt_uhid_send(hog->uhid, &ev);
> +
> + if (err < 0) {
> + error("bt_uhid_send: %s", strerror(-err));
> + return;
> + }
> +
> + hog->uhid_created = false;
> +}
> +
> void bt_hog_detach(struct bt_hog *hog)
> {
> GSList *l;
> @@ -1660,6 +1753,7 @@ void bt_hog_detach(struct bt_hog *hog)
> queue_foreach(hog->gatt_op, (void *) cancel_gatt_req, NULL);
> g_attrib_unref(hog->attrib);
> hog->attrib = NULL;
> + uhid_destroy(hog);
> }
>
> int bt_hog_set_control_point(struct bt_hog *hog, bool suspend)
> --
> 2.26.2
>
--
Luiz Augusto von Dentz
