Re: [PATCH v9 04/39] component: alloc component_match without any comp to match

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Wed, Dec 19, 2018 at 02:42:45PM +0100, Daniel Vetter wrote:
> On Thu, Dec 13, 2018 at 09:31:06AM +0530, Ramalingam C wrote:
> > If all the components associated to a component master is not added
> > to the component framework due to the HW capability or Kconfig
> > selection, component_match will be NULL at
> > component_master_add_with_match().
> > 
> > To avoid this, component_match_alloc() is added to the framework,
> > to allcoate the struct component_match with zero associated components.
> > Hence component master can be added with a component_match with zero
> > associated components.
> > 
> > This helps the component master bind call to get triggered,
> > even if no component is registered for that particular master.
> > 
> > This is meant for big PCI device drivers where small/optional
> > features are external components, and based on usecases different
> > combination of components are build as entire driver.
> > 
> > In such PCI device driver Load, if we use the component master for
> > waiting for few  components(features) availability, only if they are
> > supported by the underlying HW, then we need to allocate memory for
> > component_match using the API introduced in this change before
> > the call to component_master_add_with_match.
> > 
> > v2:
> >   No Change.
> > 
> > Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
> > Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > Cc: Kate Stewart <kstewart@linuxfoundation.org>
> > Cc: Thomas Gleixner <tglx@linutronix.de>
> > Cc: Philippe Ombredanne <pombredanne@nexb.com>
> > Cc: linux-kernel@vger.kernel.org
> 
> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> 
> Greg, I expect the i915 feature that needs this will only land in 4.22.
> I'm also not aware of anyone else using this (all the other component
> users always use components). How do you want to get this landed?
> 
> I think either getting this into 4.21, or an ack for merging through drm
> trees would work well for us.

I have no objection to you taking this through the drm tree.  As I
really do not know the component code at all (that would be Russell
King), feel free to add my:

	Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

as it looks sane to me.

thanks,

greg k-h