On Wed, 2009-05-13 at 18:57 +0800, ext Li Yang wrote:

cc'ed LKML

On Tue, May 12, 2009 at 5:17 PM, Jan Neskudla [off-list ref] wrote:

quoted

Hallo

we'd likes to use a RapidIO as a general communication bus on our new
product, and so I have some questions about general design of Linux RIO
subsystem. I did not find any better mailing list for RapidIO
discussion.

[1] - we'd like to implement following features
   * Hot-plug (hot-insert/hot-remove) of devices
   * Error handling (port-write packets - configuration, handling of
them)
   * Static ID configuration based on port numbers
   * Aux driver - basic driver, for sending messages over different
mboxes, handling ranges of doorbells

   Is it here anyone who is working on any improvement, or anyone who
knows the development plans for RapidIO subsystem?

AFAIK, there is no one currently working on these features for Linux.
It will be good if you can add these useful features.

Yes it looks like that, currently we are analyzing current rapidIO
system, and how we can add these features. 

quoted

[2] - I have a following problem with a current implementation of
loading drivers. The driver probe-function call is based on comparison
of VendorID (VID) and DeviceID (DID) only. Thus if I have 3 devices with
same DID and VID connected to the same network (bus), the driver is
loaded 3times, instead only once for the actual device Master port.

This should be the correct way as you actually have 3 instances of the device.

quoted

Rionet driver solved this by enabling to call initialization function
just once, and it expect that this is the Master port.

Rionet is kind of special.  It's not working like a simple device
driver, but more like a customized protocol stack to support multiple
ethernet over rio links.

quoted

Is it this correct behavior  ? It looks to me that RapidIO is handled
like a local bus (like PCI)

This is correct behavior.  All of them are using Linux device/driver
infrastructure, but rionet is a special device.

But I do not have a 3 devices on one silicon. I am talking about 3
devices (3 x EP8548 boards + IDT switch) connected over rapidIO through
the switch. And in this case I'd like to have only one driver siting on
the top of Linux RapidIO subsystem. I don't see the advantage of loading
a driver locally for remote device. Am I missing something  ?

And one more think, I am getting so much Bus errors OOPSes. Whenever
there is a problem with a comunication over Rio I get such a kernel OPS.
I had to add some delays into some function to be able to finish the
enum+discovery process. Did you have some experience with some bigger
rio network running under linux ? 


                Jan