On 6/29/06, Marcel Holtmann <[email protected]> wrote:
> > Well, I was saying that finally I had time to look into controller to
> > host flow control and I'd like to share what I've thought to see if
> > you agree with me before I start implementing it. Ah.. another thing,
> > do you like me to send these messages to the mailing list or directly
> > to you?
>
> I am fine with using the mailing list.
Ok, I've CCed the bluez development mailing list.
> > I've thought about implementing some simple flow control. We could add
> > 5 extra fields in hci_dev structure to set if that device wants
> > controller to host flow control and also the ACL/SCO buffer sizes.
> > These fields might be something like:
> >
> > __u8 host_flow_ctl;
> > __u16 acl_data_len;
> > __u16 sco_data_len;
> > __u16 max_acl_pkts;
> > __u16 max_sco_pkts;
> >
> > When the device is registered we can set flow control with the "Set
> > Controller to Host Flow Control" command and set the buffer sizes with
> > the "Host Buffer Size" command (if the device wants controller to host
> > flow control, of course).
>
> We also need the "Host Buffer Size" command for normal operation. The
> ISSC based dongles for example tend to send to much data which we can't
> handle smoothly.
Hmm.. I don't know if I understood. Do you mean we need to send the
host buffer size command more than once?
> > Besides that we'd need a counter per connection to be able to report
> > how many packets were completed per connection handle with the "Host
> > Number of Completed Packets" command. The counter per connection can
> > be a field like the following in hci_conn:
> >
> > __u16 nr_compl_pkts;
>
> I prefer to have an atomic counter here.
Of course. I wanted an atomic counter but have written __u16.
> > We'll have to define when we're going to send the "Host Number of
> > Completed Packets" command. The specification says we should send this
> > command when "the corresponding buffer space has been freed on the
> > Host", so we can do it this way. What do you think?
>
> For starters we can send it after every data packet, but that is not
> what we really want. We might wanna have something like 8 outstanding
> packets.
Ok.
Best regards,
-- Ulisses