linux.hci: fix stop advertise on new connection

[rkjdid]

this line was a no-op, thus allowing multiple simultaneous connections, since it was just re-sending 1 (h.params.advEnable equals 1 from line above)

[rkjdid]

For #49, I think the better fix is to only re-enable advertising upon disconnection. A completed connection should not re-enable advertising since only one central connection is allowed. Note that the spec allows for multiple central connections but as far as I have seen, this is not well supported or often used.

I think we're on the same page, and this is what I tried to fix here.

From what I understand on how it's supposed to work, and how it does work with this patch:

• disable advertising on connection complete (https://github.com/go-ble/ble/pull/49/files#diff-b4cc0f5fcbe12994ce01c868ee39ec66R504),
• enable advertising on disconnection complete (https://github.com/go-ble/ble/pull/49/files#diff-b4cc0f5fcbe12994ce01c868ee39ec66R533),

Without this patch, advertising is enabled both on connection and disconnection (resulting in the host being always available for connection).

I've just tested it without the patch, tbh it seems to be working fine with at least 2 simultaneous connections. I don't know the spec, but it didn't suit my specific usecase since I only want one connection at a time, and reading at the code & comment I thought it was also the intent minus a bug. But maybe another approach, since simul connections seem to be working fine (and is allowed per spec?), is to add a setting specifying max nb of live conn allowed, and stop advertising if reached.

[estutzenberger]

Ahh, I see now looking more closely at the code. I think the behavior change by this MR makes sense for the time being and was the intended behavior of the original authors.