Am Montag, 16. November 2015, 16:52:06 schrieb Liviu Dudau:
On Mon, Nov 16, 2015 at 04:30:16PM +0000, Russell King - ARM Linux wrote:
I've tweaked your patch to make the above (buggy) change a little clearer.
On Mon, Nov 16, 2015 at 02:44:53PM +0000, Liviu Dudau wrote:
for (i = 0;; i++) {
port = of_parse_phandle(np, "ports", i);if (!port)break;if (!of_device_is_available(port->parent)) {of_node_put(port);continue;}component_match_add(dev, &match, compare_of, port->parent);of_node_put(port);}
-static int compare_of(struct device *dev, void *data) -{
- struct device_node *np = data;
- return dev->of_node == np;
-}
The original above passes port->parent to component_match_add(). This means 'np' in the above compare_of() function is 'port->parent'.
This means the above comparison is effectively: dev->of_node == port->parent
The generic code instead does this: component_match_add(dev, &match, compare_of, port);
So what we get in the comparison function is 'port' rather than
'port->parent':
+static int compare_port(struct device *dev, void *data)
{
- struct device_node *np = data;
- return dev->parent->of_node == np;
+}
which means the comparison is: dev->parent->of_node == port
which is a different comparison from the above.
You instead want this to be: return dev->of_node == np->parent;
Heiko, please test the above change to compare_port() - I think you'll find that will fix your issue.
Sorry, I admit I'm not very good at doing patches without being able to test them. :(
Thanks for helping on this!
Russell's hint was correct. With the compare function changed like he pointed out, I again get a working display with your patches :-)
So, thanks Russell for spotting this.
Heiko