Re: [PATCH] Bluetooth: Fix adv set removal processing.

[Luiz Augusto von Dentz <luiz.dentz@gmail.com>]

Hi Alain,

On Mon, Nov 15, 2021 at 9:07 AM Marcel Holtmann <marcel@holtmann.org> wrote:
>
> Hi Alain,
>
> > When multiple advertisement sets are active and a single instance is
> > removed, the processing of hci_cc_le_set_ext_adv_enable will result in
> > considering all advertisements as disabled since the instance has
> > already been removed from the list.
> >
> > The fix is to use the command parameters to validate the intent rather
> > than making an assumption based on the validity of the adv set.
> >
> > remove_advertising() hci0
> >
> > hci_req_add_ev() hci0 opcode 0x2039 plen 6
> > hci_req_add_ev() hci0 opcode 0x203c plen 1
> >
> > hci_remove_adv_instance() hci0 removing 2MR
> > <-- This removes instance 2 from the adv_instances list
> >
> > hci_cc_le_set_ext_adv_enable() hci0 status 0x00
> > hci_sent_cmd_data() hci0 opcode 0x2039
> > hci_cc_le_set_ext_adv_enable() adv instance 0, enabled 0
> > <-- This incorrectly assumes that all instances are
> >    being disabled while only handle 2 is being disabled.
> >
> > hci_cc_le_set_ext_adv_enable() adv instance list status - before
> > hci_cc_le_set_ext_adv_enable() adv instance 3 is 1
> > hci_cc_le_set_ext_adv_enable() adv instance 1 is 1
> > hci_cc_le_set_ext_adv_enable() HCI_LE_ADV state before: 1
> > hci_cc_le_set_ext_adv_enable() adv instance list status - after
> > hci_cc_le_set_ext_adv_enable() adv instance 3 is 0
> > hci_cc_le_set_ext_adv_enable() adv instance 1 is 0
> > hci_cc_le_set_ext_adv_enable() HCI_LE_ADV state after: 0
> > <-- This is incorrect since handle 1 and 3 are still enabled
> >    in the controller
> >
> > The fix was validated by running the ChromeOS bluetooth_AdapterAdvHealth
> > test suite.
> >
> > Reviewed-by: mcchou@chromium.org
>
> we need clear name and email in the tags please. And I also like to have Fixes: tags here as well.
>
> > Signed-off-by: Alain Michaud <alainm@chromium.org>
> >
> > ---
> >
> > net/bluetooth/hci_event.c | 8 +++++---
> > 1 file changed, 5 insertions(+), 3 deletions(-)
> >
> > diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
> > index d4b75a6cfeee..52161d04136f 100644
> > --- a/net/bluetooth/hci_event.c
> > +++ b/net/bluetooth/hci_event.c
> > @@ -1385,14 +1385,16 @@ static void hci_cc_le_set_ext_adv_enable(struct hci_dev *hdev,
> >                               if (adv->enabled)
> >                                       goto unlock;
> >                       }
> > -             } else {
> > +
> > +                     hci_dev_clear_flag(hdev, HCI_LE_ADV);
> > +             } else if (!cp->num_of_sets || !set->handle) {
> >                       /* All instances shall be considered disabled */
> >                       list_for_each_entry_safe(adv, n, &hdev->adv_instances,
> >                                                list)
> >                               adv->enabled = false;
> > -             }
> >
> > -             hci_dev_clear_flag(hdev, HCI_LE_ADV);
> > +                     hci_dev_clear_flag(hdev, HCI_LE_ADV);
> > +             }
> >       }
>
> Just checking if this wouldn’t be cleaner:
>
>                 } else {
>                         if (foo)
>                                 bar;
>
>                         hci_dev_clear_flag(hdev, HCI_LE_ADV);
>                 }

Actually this seems to already have been fixed by:

https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next.git/commit/?id=2128939fe2e771645dd88e1938c27fdf96bd1cd0

Perhaps the Chrome OS tree is outdated?

> Regards
>
> Marcel
>


-- 
Luiz Augusto von Dentz