# Re: \[PATCH 48/57\] fbdev: sh\_mobile\_meram: Allocate ICBs automatically

- From: Laurent Pinchart \<laurent.pinchart@ideasonboard.com\>
- Date: 2011-12-15 11:39:31 
- List: linux-fbdev
- Page: https://ratatoskr.run/linux-fbdev/2011/12/13462351
- Thread: https://ratatoskr.run/linux-fbdev/2011/12/13462349/t.md

```text
Hi Damian,

On Thursday 15 December 2011 03:58:12 Damian Hobson-Garcia wrote:
> Hi Laurent,
> 
> On 2011/12/13 23:02, Laurent Pinchart wrote:
> > Instead of manually specifying the ICBs to use in platform data,
> > allocate them automatically at runtime.
> > 
> > The MERAM registration function now returns a pointer to an opaque MERAM
> > object, which is passed to the update and unregistration functions.
> > 
> > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > ---
> 
> So one concern that I have about this is in regards to sharing ICBs with
> user-space drivers. Since there are user space drivers (via UIO) for blocks
> like the VEU, that may want to have access to MERAM, we need a way to
> communicate which ICBs are free to user space. With the hard-coded platform
> data we could easily assume that kernel drivers would use, for example, the
> upper 16 ICBs and so user-space drivers were free to use the lower 16.

You're right, I forgot about that :-/

> One simple temporary workaround might be to provide a range of useable ICBs
> in the platform data. The MERAM memory allocation range can always easily be
> tweaked by using the meram_resources structure.

That sounds good to me. I'll implement that.

-- 
Regards,

Laurent Pinchart
```