From mboxrd@z Thu Jan  1 00:00:00 1970
From: tj@kernel.org (Tejun Heo)
Date: Tue, 8 Jul 2014 17:40:10 -0400
Subject: [PATCH v9 3/7] ata: libahci: allow to use multiple PHYs
In-Reply-To: <20140708174900.GC16148@kwain>
References: <1404728173-20263-1-git-send-email-antoine.tenart@free-electrons.com>
 <1404728173-20263-4-git-send-email-antoine.tenart@free-electrons.com>
 <20140708134000.GC4979@htj.dyndns.org>
 <20140708170353.GA16148@kwain>
 <20140708171817.GH4979@htj.dyndns.org>
 <20140708174900.GC16148@kwain>
Message-ID: <20140708214010.GI4979@htj.dyndns.org>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

Hey,

On Tue, Jul 08, 2014 at 07:49:00PM +0200, Antoine T?nart wrote:
> > So, yeah, it's being used both as input and output and we also have
> > the arguments which affect port_map, right?  It does seem confusing.
> 
> I do see priv->port_map as being automatically set and then restricted
> if needed by the port_map input here. I don't see how that's confusing.
> The only modification is we restrict the port_map parameter to the set
> of available ports. The port_map argument affected priv->port_map before
> this patch.

It is confusing.  If you wanna pass around available ports in hpriv,
please add a separate field and replace the arguments to
save_initial_config().

> > Well, so does clk.  Let's say clk is more restricted and phy can be
> > one or more per port and thus needs to be dynamic.  If so, shouldn't
> > we at least have some correlation between phys and ports?  It bothers
> > me that now libahci is carrying random number of resources that it has
> > no idea how to associate with the ports it manages.  What if later we
> > want to involve phy driver in power managing unoccupied ports?
> 
> I see. This is a first (working) attempt to have a one node per port. I
> agree that would be nice to have a correlation between ports and PHYs.
> This can definitively be added when needed without changing the dt
> bindings as only the internal representation changes. This would also
> require to get all phys from the port nodes, which is again internal
> stuff.
> 
> Don't you think we can go by steps, and have a following up series for
> this when needed (like in a power managing series for unoccupied ports)?

I don't know.  It isn't exactly difficult to make it per-port, is it?
We already have ahci_port_priv and wouldn't the code actually be
simpler that way?

Thanks.

-- 
tejun