On Fri, Feb 07, 2014 at 07:42:04PM +0100, Jean-Francois Moine wrote:
On Fri, 7 Feb 2014 17:33:26 +0000 Russell King - ARM Linux linux@arm.linux.org.uk wrote:
On Fri, Feb 07, 2014 at 06:11:08PM +0100, Jean-Francois Moine wrote:
This patch series tries to simplify the code of simple devices in case they are part of componentised subsystems, are declared in a DT, and are not using the component bin/unbind functions.
I wonder - I said earlier today that this works absolutely fine without modification with DT, so why are you messing about with it adding DT support?
This is totally the wrong approach. The idea is that this deals with /devices/ and /devices/ only. It groups up /devices/.
It's up to the add_component callback to the master device to decide how to deal with that.
Jean-Francois Moine (2): drivers/base: permit base components to omit the bind/unbind ops
And this patch has me wondering if you even understand how to use this... The master bind/unbind callbacks are the ones which establish the "card" based context with the subsystem.
Please, before buggering up this nicely designed implementation, please /first/ look at the imx-drm rework which was posted back in early January which illustrates how this is used in a DT context - which is something I've already pointed you at once today already.
As I told in a previous mail, your code works fine in my DT-based Cubox. I am rewriting the TDA988x as a normal encoder/connector, and, yes, the bind/unbind functions are useful in this case.
So, which bit of "I've already got that" was missed?
But you opened a door. In a DT context, you know that the probe_defer mechanism does not work correctly. Your work permits to solve delicate cases: your component_add tells exactly when a device is available, and the master bind callback is the green signal for the device waiting for its resources. Indeed, your system was not created for such a usage, but it works as it is (anyway, the component bind/unbind functions may be empty...).
Sorry. Deferred probe does work, it's been tested with imx-drm, not only from the master component but also the sub-components. There's no problem here.
And no component bind/unbind function should ever be empty.
Again, I put it to you that you don't understand this layer.