Re: [PATCH 3/4] OMAP: DSS2: Handle manager change in apply

[Tomi Valkeinen <tomi.valkeinen@ti.com>]

On Fri, 2011-09-02 at 12:20 +0530, Archit Taneja wrote:
> On Monday 22 August 2011 01:57 PM, Valkeinen, Tomi wrote:
> > Currently when changing the manager of an overlay, set_manager()
> directly
> > calls dispc to set the overlay's destination.
> >
> > Change this to be more in line with other overlay configurations,
> and
> > this will also remove the need to have dispc clocks enabled when
> calling
> > set_manager().
> >
> > A new field is added to overlay struct, "manager_changed". This is
> > similar to "display_changed" field in manager struct, and is used to
> > inform apply that the manager has changed and thus write to the
> > registers is needed.
> 
> I was wondering if it would be better to create an overlay_info
> member 
> called 'channel_out' rather than having 'manager_enabled' at a higher 
> level? This way, we won't need to do some of the things below(I have 
> pointed them out): 

The overlay_info is written by the users of the DSS. So if we had
channel_out there, we'd need to remove the set/get_manager() functions.
I made those functions in the first place as I felt changing the manager
is a bit bigger operation than the normal overlay attributes. Changing
the manager does effect both the old and the new managers. While I don't
think we currently do anything related to that, I believe it would be
needed for optimizations like FIFO merge.

It could perhaps be possible to change this so that the overlay_info has
the channel_out parameter, but that would be a bit bigger change, and
would needs lots of testing. So I feel this is a safer change, and it
fixes a problem we had with DRM.

 Tomi