Re: [PATCH v2 10/35] brcmfmac: firmware: Allow platform to override macaddr

[Hector Martin]

On 09/01/2022 05.14, Arend van Spriel wrote:
> On 1/4/2022 8:26 AM, Hector Martin wrote:
>> On Device Tree platforms, it is customary to be able to set the MAC
>> address via the Device Tree, as it is often stored in system firmware.
>> This is particularly relevant for Apple ARM64 platforms, where this
>> information comes from system configuration and passed through by the
>> bootloader into the DT.
>>
>> Implement support for this by fetching the platform MAC address and
>> adding or replacing the macaddr= property in nvram. This becomes the
>> dongle's default MAC address.
>>
>> On platforms with an SROM MAC address, this overrides it. On platforms
>> without one, such as Apple ARM64 devices, this is required for the
>> firmware to boot (it will fail if it does not have a valid MAC at all).
> 
> What overrides what. Can you elaborate a bit?

The behavior seems to be:

- Use the NVRAM MAC address, if any
- Use the SROM MAC address, if any
- Fail to boot

So a platform with a module containing a MAC address may choose to
override it using the DT mechanism with this patch. This is consistent
with the behavior of other drivers implementing platform MAC support.

-- 
Hector Martin (marcan@xxxxxxxxx)
Public Key: https://mrcn.st/pub