I agree with the suggested improvements.
It is indeed not trivial to configure all this settings. Based on the value
set for NIMBLE_OPT_MAX_CONNECTIONS, the default config should be set
accordingly.
Back to my issue, I'm still getting the same error.
Here's the complete config in my code:
/* Configure the host. */
cfg = ble_hs_cfg_dflt;
cfg.max_hci_bufs = 16;
// cfg.max_connections = MAX_CONNECTIONS*3;
// cfg.max_gattc_procs = 5;
cfg.max_l2cap_chans = cfg.max_connections * 3;
// cfg.max_l2cap_sig_procs = 1;
// cfg.sm_bonding = 1;
// cfg.sm_our_key_dist = BLE_SM_PAIR_KEY_DIST_ENC;
// cfg.sm_their_key_dist = BLE_SM_PAIR_KEY_DIST_ENC;
// cfg.store_read_cb = ble_store_ram_read;
// cfg.store_write_cb = ble_store_ram_write;
/* Populate config with the required GATT server settings. */
// cfg.max_attrs = 0;
// cfg.max_services = 0;
// cfg.max_client_configs = 0;
I commented most of them after reading your email. I've tried with and without
all of them set (from blecent).
\--
**Marco Ferreira**
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On Jul 23 2016, at 2:26 pm, Christopher Collins <[email protected]>
wrote:
> On Sat, Jul 23, 2016 at 09:11:43AM +0000, Marco Ferreira wrote:
> > Hi all,
> >
> > While my Central is trying to connect to the second peripheral, it
fails with
> > reason BLE_HS_ENOMEM (6).
>
> Is this error code returned by ble_gap_connect()? If so, one of the
> following settings is too low:
>
> * cfg.max_connections
> * cfg.max_l2cap_chans
> * cfg.max_client_configs
>
> Just a wild guess, but I would bet the problem is too few l2cap
> channels. I think pretty much everyone agrees that getting the host
> configuration right is too difficult, so this is something that will
> need to be improved (more about this below). In the meantime, the
> following code should ensure sufficient resources:
>
> cfg = ble_hs_cfg_dflt;
> cfg.max_l2cap_chans = cfg.max_connections * 3;
>
> cfg.max_connections gets properly assigned NIMBLE_OPT_MAX_CONNECTIONS by
> by the first line (cfg = ble_hs_cfg_dflt).
>
> cfg.max_l2cap_chans must always be greater than or equal to three times
> the number of connections.
>
> cfg.max_client_configs gets populated automatically when the various
> GATT services are initialized (e.g., ble_svc_gap_init()), so you
> probably don't need to do anything different there.
>
> Regarding future improvements to the host- I can think of a few easy
> ones, listed below. If anyone has any other ideas, please feel free to post
them to
> the list.
>
> 1\. ble_hs_cfg_dflt should contain the correct value for max_l2cap_chans.
> Currently it is initialized with the arbitrary value of 16.
>
> 2\. When something fails due to resource shortage, a specific diagnostic
> should get printed to the debug log.
>
> Thanks,
> Chris
