[PATCH 1/3] ipmi/bt-bmc: change compatible node to 'aspeed,ast2400-ibt-bmc'

Cédric Le Goater clg at kaod.org
Tue Nov 8 07:52:43 PST 2016

On 11/07/2016 02:02 PM, Arnd Bergmann wrote:
> On Wednesday, November 2, 2016 3:28:01 PM CET Cédric Le Goater wrote:
>> On 11/02/2016 02:56 PM, Joel Stanley wrote:
>>> On Wed, Nov 2, 2016 at 11:45 PM, Arnd Bergmann <arnd at arndb.de> wrote:
>>>> On Wednesday 02 November 2016, Cédric Le Goater wrote:
>>>>> The Aspeed SoCs have two BT interfaces : one is IPMI compliant and the
>>>>> other is H8S/2168 compliant.
>>>>> The current ipmi/bt-bmc driver implements the IPMI version and we
>>>>> should reflect its nature in the compatible node name using
>>>>> 'aspeed,ast2400-ibt-bmc' instead of 'aspeed,ast2400-bt-bmc'. The
>>>>> latter should be used for a H8S interface driver if it is implemented
>>>>> one day.
>>>>> Signed-off-by: Cédric Le Goater <clg at kaod.org>
>>>> We generally try to avoid changing the compatible strings after the
>>>> fact, but it's probably ok in this case.
>> As the device tree changes are not merged yet, we thought we had some 
>> more time to fine tune the naming. 
> Ok, I see. No problem then.
>>>> I don't understand who decides which of the two interfaces is used:
>>>> is it the same register set that can be driven by either one or the
>>>> other driver, or do you expect to have two drivers that can both
>>>> be active in the same system and talk to different hardware once
>>>> you get there?
>>> It's the second case. The H8S BT has a different register layout so it
>>> would require a different driver.
>> yes.
>>> We don't yet have a driver for the other BT device, but there was
>>> recent talk of using it as an alternate (non-ipmi channel) between the
>>> BMC and the host. Before that discussion I wasn't aware that the H8S
>>> BT existed. I suggested we fix this up before it hits a final release.
>>> Cédric, do you think ast2400-ibt-bmc or ast2400-ipmi-bt-bmc does a
>>> better job of describing the hardware here?
>> The specs refer to the two interfaces as BT (non IPMI) and iBT (IPMI). 
>> I think we can keep the same naming.
> Ok
>>> While we're modifying the binding, should we add a compat string for
>>> the ast2500?
>> Well, if the change in this patch is fine for all, may be we can add 
>> the ast2500 compat string in a followup patch ?
> Sounds good to me.

OK. So, how do we proceed with this patch ? Who would include it in its 
tree ? 



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