[openib-general] [PATCH] initial CM module

[frank zago]

Hi Sean,

>This patch adds in the initial CM API and module code.  The module loads,
>unloads, and allocates/deallocates connection structures, but that's about it. 
>This patch does not include changes needed to Kconfig or the Makefile, since I'm
>not sure that it makes sense to change these yet.
>
>I will commit this unless there are any objections.
>[...]
>
>+int ib_send_cm_req(struct ib_cm_id *cm_id,
>+		   struct ib_cm_req_param *param);
>+
>
>+int ib_send_cm_rep(struct ib_cm_id *cm_id,
>+		   struct ib_cm_req_param *param);
>+
>+int ib_send_cm_rtu(struct ib_cm_id *cm_id,
>+		   void *private_data,
>+		   u8 private_data_len);
>  
>

I've used several CM and I found this kind of interface to be painful to 
use.
I'd rather see an interface similar to Topspin's where you register a CM 
callback, get CM events and react (or not) to these.

With the interface you propose it takes maybe 200 lines of code to 
establish a simple connection, while with a callback it can be down to 
30 lines. It should be as easy as possible for an application or a 
driver to establish a connection. I shouldn't have to rewrite a CM state 
machine every time I need a connection.

Frank.