Subject: Re: [PATCH v2 1/3] Bluetooth: Add quirk for reading BD_ADDR from fwnode property

From: Matthias Kaehlcke <[email-masked]>
Date: Mon, 19 Nov 2018 13:44:15 -0800

Hi Marcel,

is this in line with what you suggested at
https://lore.kernel.org/patchwork/patch/992280/#1183789 ?

Thanks

Matthias

On Mon, Oct 29, 2018 at 05:44:13PM -0700, Matthias Kaehlcke 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 <[email-masked]>
> Reviewed-by: Balakrishna Godavarthi <[email-masked]>
> ---
> 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 <[email-masked]>' 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 c36dc1e20556..fbba43e9bef5 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 7352fe85674b..d4149005a661 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;
> +
> +	return 0;
> +}
> +
>  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);
> +
> +			if (!bacmp(&hdev->public_addr, BDADDR_ANY) ||
> +			    !hdev->set_bdaddr ||
> +			    hdev->set_bdaddr(hdev, &hdev->public_addr))
> +				hci_dev_set_flag(hdev, HCI_UNCONFIGURED);
> +		}
> +
> +setup_failed:
>  		/* The transport driver can set these quirks before
>  		 * creating the HCI device or in its setup callback.
>  		 *
> diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
> index ccce954f8146..fae84353d030 100644
> --- a/net/bluetooth/mgmt.c
> +++ b/net/bluetooth/mgmt.c
> @@ -551,7 +551,8 @@ static bool is_configured(struct hci_dev *hdev)
>  	    !hci_dev_test_flag(hdev, HCI_EXT_CONFIGURED))
>  		return false;
>  
> -	if (test_bit(HCI_QUIRK_INVALID_BDADDR, &hdev->quirks) &&
> +	if ((test_bit(HCI_QUIRK_INVALID_BDADDR, &hdev->quirks) ||
> +	     test_bit(HCI_QUIRK_USE_BDADDR_PROPERTY, &hdev->quirks)) &&
>  	    !bacmp(&hdev->public_addr, BDADDR_ANY))
>  		return false;
>  
> @@ -566,7 +567,8 @@ static __le32 get_missing_options(struct hci_dev *hdev)
>  	    !hci_dev_test_flag(hdev, HCI_EXT_CONFIGURED))
>  		options |= MGMT_OPTION_EXTERNAL_CONFIG;
>  
> -	if (test_bit(HCI_QUIRK_INVALID_BDADDR, &hdev->quirks) &&
> +	if ((test_bit(HCI_QUIRK_INVALID_BDADDR, &hdev->quirks) ||
> +	     test_bit(HCI_QUIRK_USE_BDADDR_PROPERTY, &hdev->quirks)) &&
>  	    !bacmp(&hdev->public_addr, BDADDR_ANY))
>  		options |= MGMT_OPTION_PUBLIC_ADDRESS;
>