Hi Luiz,
I sent a v2 that changes the cache to use gatt_db. Please take another
look. Thanks!
On Tue, Dec 8, 2020 at 5:58 PM Luiz Augusto von Dentz
<luiz.dentz@xxxxxxxxx> wrote:
>
> Hi Sonny,
>
> On Tue, Dec 8, 2020 at 5:16 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.
>
> While the idea is pretty good we need to find a way to persist it
> across reboots/restarts. In theory we could save the value on the
> gatt_db instance and then make changes to device.c:store_desc to
> attempt to read if there is a value stored in the db save it on file
> as well so the next time the cache is loaded it should restore the
> report map, or any other descriptor that have its value saved in the
> database. That said we may need to introduce some sort of property for
> values stored in the db since normally the values store in the
> database shall not be persisted on file, in fact it would cause a lot
> of fime access updating the cache if we were to trigger updates
> everytime the db is updated with a value.
>
> > Reviewed-by: Alain Michaud <alainm@xxxxxxxxxxxx>
> >
> > ---
> > profiles/input/hog-lib.c | 142 ++++++++++++++++++++++++++-------------
> > 1 file changed, 96 insertions(+), 46 deletions(-)
> >
> > diff --git a/profiles/input/hog-lib.c b/profiles/input/hog-lib.c
> > index ee811d301..1e198ea64 100644
> > --- a/profiles/input/hog-lib.c
> > +++ b/profiles/input/hog-lib.c
> > @@ -95,6 +95,8 @@ struct bt_hog {
> > struct queue *bas;
> > GSList *instances;
> > struct queue *gatt_op;
> > + uint8_t report_map[HOG_REPORT_MAP_MAX_SIZE];
> > + ssize_t report_map_len;
> > };
> >
> > struct report {
> > @@ -276,6 +278,8 @@ static void find_included(struct bt_hog *hog, GAttrib *attrib,
> > free(req);
> > }
> >
> > +static void uhid_create(struct bt_hog *hog);
> > +
> > static void report_value_cb(const guint8 *pdu, guint16 len, gpointer user_data)
> > {
> > struct report *report = user_data;
> > @@ -924,57 +928,17 @@ 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)
> > {
> > - struct gatt_request *req = user_data;
> > - struct bt_hog *hog = req->user_data;
> > - uint8_t value[HOG_REPORT_MAP_MAX_SIZE];
> > struct uhid_event ev;
> > - ssize_t vlen;
> > - char itemstr[20]; /* 5x3 (data) + 4 (continuation) + 1 (null) */
> > - int i, err;
> > GError *gerr = NULL;
> > + int i, err;
> >
> > - 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");
> > + if (!hog->report_map_len) {
> > + warn("Failed to initiate UHID_CREATE without report map");
> > return;
> > }
> >
> > - DBG("Report MAP:");
> > - for (i = 0; i < vlen;) {
> > - ssize_t ilen = 0;
> > - bool long_item = false;
> > -
> > - if (get_descriptor_item_info(&value[i], vlen - i, &ilen,
> > - &long_item)) {
> > - /* Report ID is short item with prefix 100001xx */
> > - if (!long_item && (value[i] & 0xfc) == 0x84)
> > - hog->has_report_id = TRUE;
> > -
> > - DBG("\t%s", item2string(itemstr, &value[i], ilen));
> > -
> > - i += ilen;
> > - } else {
> > - error("Report Map parsing failed at %d", i);
> > -
> > - /* Just print remaining items at once and break */
> > - DBG("\t%s", item2string(itemstr, &value[i], vlen - i));
> > - break;
> > - }
> > - }
> > -
> > - /* create uHID device */
> > memset(&ev, 0, sizeof(ev));
> > ev.type = UHID_CREATE;
> >
> > @@ -1004,8 +968,8 @@ static void report_map_read_cb(guint8 status, const guint8 *pdu, guint16 plen,
> > ev.u.create.version = hog->version;
> > ev.u.create.country = hog->bcountrycode;
> > ev.u.create.bus = BUS_BLUETOOTH;
> > - ev.u.create.rd_data = value;
> > - ev.u.create.rd_size = vlen;
> > + ev.u.create.rd_data = hog->report_map;
> > + ev.u.create.rd_size = hog->report_map_len;
> >
> > err = bt_uhid_send(hog->uhid, &ev);
> > if (err < 0) {
> > @@ -1018,6 +982,62 @@ static void report_map_read_cb(guint8 status, const guint8 *pdu, guint16 plen,
> > bt_uhid_register(hog->uhid, UHID_SET_REPORT, set_report, hog);
> >
> > hog->uhid_created = true;
> > +}
> > +
> > +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;
> > + ssize_t vlen;
> > + char itemstr[20]; /* 5x3 (data) + 4 (continuation) + 1 (null) */
> > + int i;
> > +
> > + 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, hog->report_map,
> > + sizeof(hog->report_map));
> > + if (vlen < 0) {
> > + error("ATT protocol error");
> > + return;
> > + }
> > +
> > + hog->report_map_len = vlen;
> > +
> > + DBG("Report MAP:");
> > + for (i = 0; i < vlen;) {
> > + ssize_t ilen = 0;
> > + bool long_item = false;
> > +
> > + if (get_descriptor_item_info(&hog->report_map[i], vlen - i,
> > + &ilen, &long_item)) {
> > + /* Report ID is short item with prefix 100001xx */
> > + if (!long_item && (hog->report_map[i] & 0xfc) == 0x84)
> > + hog->has_report_id = TRUE;
> > +
> > + DBG("\t%s", item2string(itemstr, &hog->report_map[i],
> > + ilen));
> > +
> > + i += ilen;
> > + } else {
> > + error("Report Map parsing failed at %d", i);
> > +
> > + /* Just print remaining items at once and break */
> > + DBG("\t%s", item2string(itemstr, &hog->report_map[i],
> > + vlen - i));
> > + break;
> > + }
> > + }
> > +
> > + /* create uHID device */
> > + uhid_create(hog);
> >
> > DBG("HoG created uHID device");
> > }
> > @@ -1602,6 +1622,12 @@ bool bt_hog_attach(struct bt_hog *hog, void *gatt)
> > bt_hog_attach(instance, gatt);
> > }
> >
> > + /* Try to initiate UHID_CREATE if we already have the report map to
> > + * avoid re-reading the report map from the peer device.
> > + */
> > + if (hog->report_map_len > 0)
> > + uhid_create(hog);
> > +
> > if (!hog->uhid_created) {
> > DBG("HoG discovering characteristics");
> > if (hog->attr)
> > @@ -1627,6 +1653,29 @@ 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 +1709,7 @@ 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
