Re: [PATCH 2/3] can: c_can: Provide generic interface to configure c-can message objects

[Amit Virdi <amit.virdi@st.com>]

On 12/21/2012 1:43 AM, Wolfgang Grandegger wrote:
> On 12/20/2012 03:04 PM, Marc Kleine-Budde wrote:
>> On 12/20/2012 11:05 AM, Amit Virdi wrote:
>>> Depending on the underlying platform, the configuration of the c-can
>>> message objects can change. For e.g. in some systems, it makes more
>>> sense to receive many message objects and transmit very few. In any
>>> case, providing flexibility in configuring the message objects is highly
>>> desirable.
>>>
>>> The total number of message objects for C_CAN controller is fixed at 32.
>>> The receive message objects are assigned higher priority so they begin
>>> with message object#1. So, in order to configure the message object the
>>> driver just needs two parameters - rx_split (for differentiating between
>>> lower bucket and higher bucket) and tx_num.
>>>
>>> However, if the user doesn't specify these parameters, then the message
>>> objects are configured with default parameters with equal distribution
>>> of receive and transmit message objects (16 each).
>>
>> As Wolfgang pointed out, the DT should only describe the hardware. In
>> the ethernet world I think there is ethtool to configure the hardware.
>> Maybe we need something similar for CAN (or add CAN support to ethtool).
>
> Yeah, a simple tool using simple ioctl request would be nice, indeed.
> Well, as a per device setting seems overkill a simple module parameter
> would just do it.
>

So, you're saying to drop the device configuration from the DT and use 
some tool to do that. This would be nice if there are enough devices, 
apart from the Bosch C-CAN controller, which require this sort of 
configuration.

Regards
Amit Virdi