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

[Wolfgang Grandegger <wg@grandegger.com>]

On 01/16/2013 08:45 AM, Amit Virdi wrote:
> 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.

No, I said: "a simple module parameter would just do it".

Wolfgang.