Re: [PATCH 7/8] Bluetooth: Add new mgmt setting for LE advertising

Hi,

On Tue, Sep 24, 2013, Johan Hedberg wrote:

On Tue, Sep 24, 2013, Anderson Lizardo wrote:

quoted

On Tue, Sep 24, 2013 at 10:02 AM,  [off-list ref] wrote:

quoted

This patch adds a new mgmt setting for LE advertising and hooks up the
necessary places in the mgmt code to operate on the HCI_LE_PERIPHERAL
flag (which corresponds to this setting). This patch does not yet add
any new command for enabling the setting - that is left for a subsequent
patch.

How this code behaves if we enable/disable LE advertising using
hciconfig hci0 leadv/noleadv? IIRC the LE_SET_ADV_ENABLE command will
fail if advertising is already set on the controller.

You're right that a mix of mgmt and hciconfig will mix things up on the
kernel side. This is something I was aware of but didn't investigate
much further since I was assuming it would add too much complexity to
the code. The principle has always been that we keep compatibility/good
behavior with mixed mgmg/raw HCI access only as long as it doesn't
needlessly complicate the code.

That said, I'll take a another look if the flag setting could be moved
to a hci_event.c handler from the request callback without requiring the
addition of a second flag or state variable. This issue is not unique to
this new setting but actually exists for many of them. What we probably
need is a generic mgmt_send_new_settings function that hci_event.c
handlers can call when they know that new_settings should be emitted. I
suspect that might solve the issue.

So I did take another look and this gets tricky since we don't just need
to emit a new_settings, but also ensure that it does not get emitted on
the mgmt socket that may have caused the command to be sent. Therefore,
I decided against trying to have "full" support of mixing mgmt with raw
HCI. What I did do is ensure that our dev_flags remain correct by using
the hci_event.c handler to set them. This ensures that subsequent mgmt
commands still work even though bluetoothd may not always be completely
up to date with these settings.

Johan