Re: [PATCH 1/2] Replace hook-based with flag-based approach for choosing video mode

[Robert Millan <rmh@aybabtu.com>]

On Fri, Aug 21, 2009 at 02:54:32PM +0200, Vladimir 'phcoder' Serbinenko wrote:
> On Mon, Aug 17, 2009 at 3:51 PM, Robert Millan<rmh@aybabtu.com> wrote:
> > On Sun, Aug 16, 2009 at 08:51:06PM +0200, Vladimir 'phcoder' Serbinenko wrote:
> >> After discussion on IRC it revealed that hook-based approach is
> >> unpracticable because number of available modes grows exponentially
> >> with every parameter available. Here is the patch to change to
> >> flag-based approach
> >
> > Please can you ellaborate on this?  (if you still have a copy of the
> > discussion, it'd be useful to post it)
> >
> There was no discussion on this point. But current design is to call a
> hook with every available mode and see if it approves the mode.
> Unfortunately it doesn't work as expected because some modes aren't
> presented by driver unless explicitly requested. This may cause
> appropriate mode to be missed. Making driver iterate through a lot of
> modes will slow down mode switching. With flag-based approach driver
> knows which mode upper layer wants and so can present appropriate one.
> It has a drawback of limiting number of filtering possibilities but
> currently no subsystem needs more than is done with this patch. If it
> changes in the future interface can be extended to have new flags or
> parameters

Thank you.

-- 
Robert Millan

  The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and
  how) you may access your data; but nobody's threatening your freedom: we
  still allow you to remove your data and not access it at all."