diff mbox

[2/2] drm/rockchip: Convert the probe function to the generic drm_of_component_probe()

Message ID 1447685093-26129-3-git-send-email-Liviu.Dudau@arm.com
State Superseded
Headers show

Commit Message

Liviu Dudau Nov. 16, 2015, 2:44 p.m. UTC 
Take two: Initial attempt to convert rockchip to drm_of_component_probe()
missed the difference between ports and encoders when using the
compare_of() function. Now that drm_of_component_probe() has been enhanced,
let's try again the conversion.

Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
---
 drivers/gpu/drm/rockchip/rockchip_drm_drv.c | 98 ++++++-----------------------
 1 file changed, 18 insertions(+), 80 deletions(-)

Comments

Liviu Dudau Nov. 16, 2015, 4:52 p.m. UTC | #1 
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!

Liviu

> 
> Thanks.
> 
> -- 
> FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
> according to speedtest.net.
>
diff mbox

Patch

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
index f22e1e1..581e98c 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
@@ -19,6 +19,7 @@ 
 #include <drm/drmP.h>
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_fb_helper.h>
+#include <drm/drm_of.h>
 #include <linux/dma-mapping.h>
 #include <linux/pm_runtime.h>
 #include <linux/module.h>
@@ -411,36 +412,6 @@  int rockchip_drm_encoder_get_mux_id(struct device_node *node,
 }
 EXPORT_SYMBOL_GPL(rockchip_drm_encoder_get_mux_id);
 
-static int compare_of(struct device *dev, void *data)
-{
-	struct device_node *np = data;
-
-	return dev->of_node == np;
-}
-
-static void rockchip_add_endpoints(struct device *dev,
-				   struct component_match **match,
-				   struct device_node *port)
-{
-	struct device_node *ep, *remote;
-
-	for_each_child_of_node(port, ep) {
-		remote = of_graph_get_remote_port_parent(ep);
-		if (!remote || !of_device_is_available(remote)) {
-			of_node_put(remote);
-			continue;
-		} else if (!of_device_is_available(remote->parent)) {
-			dev_warn(dev, "parent device of %s is not available\n",
-				 remote->full_name);
-			of_node_put(remote);
-			continue;
-		}
-
-		component_match_add(dev, match, compare_of, remote);
-		of_node_put(remote);
-	}
-}
-
 static int rockchip_drm_bind(struct device *dev)
 {
 	struct drm_device *drm;
@@ -481,63 +452,30 @@  static const struct component_master_ops rockchip_drm_ops = {
 	.unbind = rockchip_drm_unbind,
 };
 
-static int rockchip_drm_platform_probe(struct platform_device *pdev)
+static int compare_port(struct device *dev, void *data)
 {
-	struct device *dev = &pdev->dev;
-	struct component_match *match = NULL;
-	struct device_node *np = dev->of_node;
-	struct device_node *port;
-	int i;
+	struct device_node *np = data;
 
-	if (!np)
-		return -ENODEV;
-	/*
-	 * Bind the crtc ports first, so that
-	 * drm_of_find_possible_crtcs called from encoder .bind callbacks
-	 * works as expected.
-	 */
-	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;
-		}
+	return dev->parent->of_node == np;
+}
 
-		component_match_add(dev, &match, compare_of, port->parent);
-		of_node_put(port);
-	}
+static int compare_encoder(struct device *dev, void *data)
+{
+	struct device_node *np = data;
 
-	if (i == 0) {
-		dev_err(dev, "missing 'ports' property\n");
-		return -ENODEV;
-	}
+	return dev->of_node == np;
+}
 
-	if (!match) {
-		dev_err(dev, "No available vop found for display-subsystem.\n");
-		return -ENODEV;
-	}
-	/*
-	 * For each bound crtc, bind the encoders attached to its
-	 * remote endpoint.
-	 */
-	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;
-		}
+static int rockchip_drm_platform_probe(struct platform_device *pdev)
+{
+	int ret = drm_of_component_probe(&pdev->dev, compare_port,
+					 compare_encoder, &rockchip_drm_ops);
 
-		rockchip_add_endpoints(dev, &match, port);
-		of_node_put(port);
-	}
+	/* keep compatibility with old code that was returning -ENODEV */
+	if (ret == -EINVAL)
+		return -ENODEV;
 
-	return component_master_add_with_match(dev, &rockchip_drm_ops, match);
+	return ret;
 }
 
 static int rockchip_drm_platform_remove(struct platform_device *pdev)