On Thu, Nov 20, 2014 at 3:57 AM, Thierry Reding thierry.reding@gmail.com wrote:
On Sun, Nov 16, 2014 at 09:18:47AM -0500, Rob Clark wrote:
On Fri, Nov 14, 2014 at 5:42 PM, Hai Li hali@codeaurora.org wrote:
All the sub-systems in mdss share the same irq. This change provides the sub-systems with the interfaces to register/unregister their own irq handlers.
With this change, struct mdp5_kms does not have to keep the hdmi or edp context.
So, I think the point of this is to better deal w/ different hw variants which do or do-not have hdmi, edp, dsi, etc..
But, just playing devil's advocate here, it seems like it would be simpler to instead just do something like:
if (priv->hdmi && (intr & MDP5_HW_INTR_STATUS_INTR_HDMI)) hdmi_irq(0, priv->hdmi); if (priv->edp && (intr & MDP5_HW_INTR_STATUS_INTR_EDP)) edp_irq(0, priv->edp); ... etc ...It is a little less elegant. But it is also less lines of code. I guess there will be plenty of necessary complexity as we add support for all mdp5 features. So avoiding some unnecessary complexity might be a good thing in the long run.
If we really did want to make it more dynamic, we could always extend 'struct mdp_irq' to take both an irq mask and an initiator id, I suppose. I'm not sure if that is overkill. AFAICT we really only have 5 different subsystems to dispatch to (mdp5 itself, and dsi0/dsi1/hdmi/edp), so simply adding some if-not-null checks in mdp5_irq() seems pretty reasonable to me.
To me this just seems like a regular interrupt multiplexer, so implementing it as an irq_chip would be the most appropriate. That way you get all the goodness of a well-tested code base for free and you can simply pass in the request_{threaded_,}irq()'s dev parameter.
yup, that is what I did here:
http://cgit.freedesktop.org/~robclark/linux/commit/?h=msm-next&id=d9a709...
there is a bit of awkwardness related to threaded handlers.. for now I don't need threaded handlers so the solution was to not use them
Thierry