[PATCH 1/3] misc: Add Aspeed BT IPMI host driver

[Cédric Le Goater]

Hello, 

On 09/12/2016 10:33 PM, Corey Minyard wrote:
> On 09/12/2016 02:15 PM, Arnd Bergmann wrote:
>> On Monday, September 12, 2016 1:55:40 PM CEST Corey Minyard wrote:
>>> On 09/02/2016 08:22 AM, Cédric Le Goater wrote:
>>>> Hello,
>>>>
>>>> Adding Corey in cc: . I guess I should have done that in the first place.
>>> Yes, probably so.  I've been travelling and didn't see it on the mailing
>>> lists until now.
>>>
>>> There is already a BT driver in the kernel, in drivers/char/ipmi, why
>>> won't that work?
>> The new driver is the host side (running on the BMC), the existing one
>> is the client (running on the PC).
>>
>>     Arnd
> 
> Ok, that's not really clear from the documentation or the Kconfig.
> In the IPMI spec the "host" side is the computer side, not the BMC
> side.  Like:
> 
>    11.6.1 BT Host Interface Registers
>    The Host BT interface provides an independent set of registers and
>    interrupts to allow the Host driver to
>    communicate with the baseboard management controller without
>    conflicting with the O/S ACPI driver.
> 
> In light of that, this should probably be named the bt-bmc driver.
> 
> I haven't reviewed this in detail, but I'm ok with putting it in
> drivers/char/ipmi.  The state machine part looks reasonably
> generic.  The configuration part isn't, but that could be split
> out later if necessary.
> 
> The biggest thing I don't like is the byte at a time interfaces
> from userspace.  That seems fairly inefficient if the system
> does extra work for each userspace access.  IIRC some
> systems do and some don't.

What about the ioctl to send an SMS ATN event to the host ? Is 
that ok for you ?

Thanks,

C.