From: Matthias Kaehlcke <mka@chromium.org>
To: Andre Heider <a.heider@gmail.com>
Cc: linux-bluetooth@vger.kernel.org
Subject: Re: "local-[bd|mac]-address" inconsistency?
Date: Mon, 18 Nov 2019 12:15:51 -0800 [thread overview]
Message-ID: <20191118201551.GJ27773@google.com> (raw)
In-Reply-To: <57775d51-7de2-a32c-8b23-aba611483f51@gmail.com>
Hi Andre,
On Mon, Nov 18, 2019 at 09:20:35AM +0100, Andre Heider wrote:
> Hi,
>
> when passing both addresses through device-tree in the same way:
> $ hexdump /proc/device-tree/soc/ethernet@5020000/local-mac-address
> 0000000 0702 3d96 53d4
>
> $ hexdump /proc/device-tree/soc/serial@5000400/bluetooth/local-bd-address
> 0000000 0703 3d96 53d4
>
> I get this for eth (which is consistent with u-boot):
> link/ether 02:07:96:3d:d4:53
>
> But for bt it's in reverse order:
> Controller 53:D4:3D:96:07:03
>
> Is this intended?
Kind of.
In both cases the address is specified in the binary format used by BT/NW
stack.
When BT addresses are printed they are converted from LSB to MSB.
> Do I really have to pass the bdaddr from u-boot in another way?
One could make a case that we don't care what the 'internal' format is and
that the BD_ADDR should be specified in MSB format in the DT, and the kernel
would be in charge of converting it to LSB. However I fear it is too late to
consider a change at this point, since the binding has been in the kernel for
6 months with the current format and existing devices may rely on it.
next prev parent reply other threads:[~2019-11-18 20:15 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-18 8:20 "local-[bd|mac]-address" inconsistency? Andre Heider
2019-11-18 20:15 ` Matthias Kaehlcke [this message]
2019-11-19 4:35 ` Andre Heider
2019-11-19 5:19 ` Marcel Holtmann
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