Hi Marcel,
thanks for the review!
On Wed, Dec 19, 2018 at 03:22:12PM +0100, Marcel Holtmann wrote:
> > Add HCI_QUIRK_USE_BDADDR_PROPERTY to allow controllers to retrieve
> > the public Bluetooth address from the firmware node property
> > 'local-bd-address'. If quirk is set and the property does not exist
> > or is invalid the controller is marked as unconfigured.
> >
> > Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
> > Reviewed-by: Balakrishna Godavarthi <bgodavar@xxxxxxxxxxxxxx>
> > Tested-by: Balakrishna Godavarthi <bgodavar@xxxxxxxxxxxxxx>
> > ---
> > Changes in v2:
> > - added check for return value of ->setup()
> > - only read BD_ADDR from the property if it isn't assigned yet. This
> > is needed to support configuration from user space
> > - refactored the branch of the new quirk to get rid of 'bd_addr_set'
> > - added 'Reviewed-by: Balakrishna Godavarthi <bgodavar@xxxxxxxxxxxxxx>' tag
> > ---
> > include/net/bluetooth/hci.h | 12 ++++++++++
> > net/bluetooth/hci_core.c | 45 +++++++++++++++++++++++++++++++++++++
> > net/bluetooth/mgmt.c | 6 +++--
> > 3 files changed, 61 insertions(+), 2 deletions(-)
> >
> > diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
> > index c36dc1e20556a..fbba43e9bef5b 100644
> > --- a/include/net/bluetooth/hci.h
> > +++ b/include/net/bluetooth/hci.h
> > @@ -158,6 +158,18 @@ enum {
> > */
> > HCI_QUIRK_INVALID_BDADDR,
> >
> > + /* When this quirk is set, the public Bluetooth address
> > + * initially reported by HCI Read BD Address command
> > + * is considered invalid. The public BD Address can be
> > + * specified in the fwnode property 'local-bd-address'.
> > + * If this property does not exist or is invalid controller
> > + * configuration is required before this device can be used.
> > + *
> > + * This quirk can be set before hci_register_dev is called or
> > + * during the hdev->setup vendor callback.
> > + */
> > + HCI_QUIRK_USE_BDADDR_PROPERTY,
> > +
> > /* When this quirk is set, the duplicate filtering during
> > * scanning is based on Bluetooth devices addresses. To allow
> > * RSSI based updates, restart scanning if needed.
> > diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
> > index 7352fe85674be..d4149005a661e 100644
> > --- a/net/bluetooth/hci_core.c
> > +++ b/net/bluetooth/hci_core.c
> > @@ -30,6 +30,7 @@
> > #include <linux/rfkill.h>
> > #include <linux/debugfs.h>
> > #include <linux/crypto.h>
> > +#include <linux/property.h>
> > #include <asm/unaligned.h>
> >
> > #include <net/bluetooth/bluetooth.h>
> > @@ -1355,6 +1356,36 @@ int hci_inquiry(void __user *arg)
> > return err;
> > }
> >
> > +/**
> > + * hci_dev_get_bd_addr_from_property - Get the Bluetooth Device Address
> > + * (BD_ADDR) for a HCI device from
> > + * a firmware node property.
> > + * @hdev: The HCI device
> > + *
> > + * Search the firmware node for 'local-bd-address'.
> > + *
> > + * All-zero BD addresses are rejected, because those could be properties
> > + * that exist in the firmware tables, but were not updated by the firmware. For
> > + * example, the DTS could define 'local-bd-address', with zero BD addresses.
> > + */
> > +static int hci_dev_get_bd_addr_from_property(struct hci_dev *hdev)
> > +{
> > + struct fwnode_handle *fwnode = dev_fwnode(hdev->dev.parent);
> > + bdaddr_t ba;
> > + int ret;
> > +
> > + ret = fwnode_property_read_u8_array(fwnode, "local-bd-address",
> > + (u8 *)&ba, sizeof(ba));
> > + if (ret < 0)
> > + return ret;
> > + if (!bacmp(&ba, BDADDR_ANY))
> > + return -ENODATA;
> > +
> > + hdev->public_addr = ba;
>
> this needs to use bacpy btw.
will change
> > +
> > + return 0;
> > +}
>
> Make this void since the return value is actually not used right now.
ok
> > +
> > static int hci_dev_do_open(struct hci_dev *hdev)
> > {
> > int ret = 0;
> > @@ -1422,6 +1453,20 @@ static int hci_dev_do_open(struct hci_dev *hdev)
> > if (hdev->setup)
> > ret = hdev->setup(hdev);
> >
> > + if (ret)
> > + goto setup_failed;
> > +
> > + if (test_bit(HCI_QUIRK_USE_BDADDR_PROPERTY, &hdev->quirks)) {
> > + if (!bacmp(&hdev->public_addr, BDADDR_ANY))
> > + hci_dev_get_bd_addr_from_property(hdev);
>
> So I would move the bacmp() into
> hci_dev_get_bd_addr_from_property. Mainly since you also write the
> field there.
Personally I'm not a fan of functions that pretend to do something and
then do it conditionally, IMO it obscures the actual code flow.
I'm open to change it though if you have a strong preference for not
having the check in hci_dev_do_open().
> > + if (!bacmp(&hdev->public_addr, BDADDR_ANY) ||
> > + !hdev->set_bdaddr ||
> > + hdev->set_bdaddr(hdev, &hdev->public_addr))
> > + hci_dev_set_flag(hdev, HCI_UNCONFIGURED);
> > + }
>
> So this one I don’t like since it makes my brain hurt when I have to read it and understand it.
I agree, it's an ugly construct.
> I think this needs to be like this:
>
> if (bacmp(&hdev->public_addr, BDADDR_ANY) &&
> hdev->set_bdaddr)
> ret = hdev->set_bdaddr(hdev, &hdev->public_addr);
> else
> err = -EADDRNOTAVAIL;
>
> That will fail the power on procedure which is the right thing to do if the local-bd-address is not present. The driver decided that it should be in DT and so enforce that.
Ok, will change as suggested.
Thanks
Matthias
