Thread (6 messages) 6 messages, 3 authors, 2015-01-13

[PATCH v7 1/3] of: Decrement refcount of previous endpoint in of_graph_get_next_endpoint

From: laurent.pinchart@ideasonboard.com (Laurent Pinchart)
Date: 2014-12-26 09:44:05
Also in: dri-devel, linux-media, lkml 

Hi Philipp,

Thank you for the patch.

On Tuesday 23 December 2014 14:09:16 Philipp Zabel wrote:
Decrementing the reference count of the previous endpoint node allows to
use the of_graph_get_next_endpoint function in a for_each_... style macro.
All current users of this function that pass a non-NULL prev parameter
(coresight, rcar-du, imx-drm, soc_camera, and omap2-dss) are changed to
not decrement the passed prev argument's refcount themselves.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: Mauro Carvalho Chehab <redacted>
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
---
Changes since v6:
 - Added omap2-dss.
 - Added Mathieu's ack.
---
 drivers/coresight/of_coresight.c                  | 13 ++-----------
 drivers/gpu/drm/imx/imx-drm-core.c                | 13 ++-----------
 drivers/gpu/drm/rcar-du/rcar_du_kms.c             | 15 ++++-----------
For rcar-du,

Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
quoted hunk ↗ jump to hunk
 drivers/media/platform/soc_camera/soc_camera.c    |  3 ++-
 drivers/of/base.c                                 |  9 +--------
 drivers/video/fbdev/omap2/dss/omapdss-boot-init.c |  7 +------
 6 files changed, 12 insertions(+), 48 deletions(-)

diff --git a/drivers/coresight/of_coresight.c
b/drivers/coresight/of_coresight.c index 5030c07..349c88b 100644
--- a/drivers/coresight/of_coresight.c
+++ b/drivers/coresight/of_coresight.c
@@ -52,15 +52,6 @@ of_coresight_get_endpoint_device(struct device_node
*endpoint) endpoint, of_dev_node_match);
 }

-static struct device_node *of_get_coresight_endpoint(
-		const struct device_node *parent, struct device_node *prev)
-{
-	struct device_node *node = of_graph_get_next_endpoint(parent, prev);
-
-	of_node_put(prev);
-	return node;
-}
-
 static void of_coresight_get_ports(struct device_node *node,
 				   int *nr_inport, int *nr_outport)
 {
@@ -68,7 +59,7 @@ static void of_coresight_get_ports(struct device_node
*node, int in = 0, out = 0;

 	do {
-		ep = of_get_coresight_endpoint(node, ep);
+		ep = of_graph_get_next_endpoint(node, ep);
 		if (!ep)
 			break;

@@ -140,7 +131,7 @@ struct coresight_platform_data
*of_get_coresight_platform_data( /* Iterate through each port to discover
topology */
 		do {
 			/* Get a handle on a port */
-			ep = of_get_coresight_endpoint(node, ep);
+			ep = of_graph_get_next_endpoint(node, ep);
 			if (!ep)
 				break;

diff --git a/drivers/gpu/drm/imx/imx-drm-core.c
b/drivers/gpu/drm/imx/imx-drm-core.c index b250130..fed627d 100644
--- a/drivers/gpu/drm/imx/imx-drm-core.c
+++ b/drivers/gpu/drm/imx/imx-drm-core.c
@@ -436,15 +436,6 @@ static uint32_t imx_drm_find_crtc_mask(struct
imx_drm_device *imxdrm, return 0;
 }

-static struct device_node *imx_drm_of_get_next_endpoint(
-		const struct device_node *parent, struct device_node *prev)
-{
-	struct device_node *node = of_graph_get_next_endpoint(parent, prev);
-
-	of_node_put(prev);
-	return node;
-}
-
 int imx_drm_encoder_parse_of(struct drm_device *drm,
 	struct drm_encoder *encoder, struct device_node *np)
 {
@@ -456,7 +447,7 @@ int imx_drm_encoder_parse_of(struct drm_device *drm,
 	for (i = 0; ; i++) {
 		u32 mask;

-		ep = imx_drm_of_get_next_endpoint(np, ep);
+		ep = of_graph_get_next_endpoint(np, ep);
 		if (!ep)
 			break;

@@ -504,7 +495,7 @@ int imx_drm_encoder_get_mux_id(struct device_node *node,
return -EINVAL;

 	do {
-		ep = imx_drm_of_get_next_endpoint(node, ep);
+		ep = of_graph_get_next_endpoint(node, ep);
 		if (!ep)
 			break;

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_kms.c
b/drivers/gpu/drm/rcar-du/rcar_du_kms.c index 0c5ee61..480c4d9 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_kms.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
@@ -206,7 +206,7 @@ static int rcar_du_encoders_init_one(struct
rcar_du_device *rcdu, enum rcar_du_encoder_type enc_type =
RCAR_DU_ENCODER_NONE;
 	struct device_node *connector = NULL;
 	struct device_node *encoder = NULL;
-	struct device_node *prev = NULL;
+	struct device_node *ep_node = NULL;
 	struct device_node *entity_ep_node;
 	struct device_node *entity;
 	int ret;
@@ -225,11 +225,7 @@ static int rcar_du_encoders_init_one(struct
rcar_du_device *rcdu, entity_ep_node = of_parse_phandle(ep->local_node,
"remote-endpoint", 0);

 	while (1) {
-		struct device_node *ep_node;
-
-		ep_node = of_graph_get_next_endpoint(entity, prev);
-		of_node_put(prev);
-		prev = ep_node;
+		ep_node = of_graph_get_next_endpoint(entity, ep_node);

 		if (!ep_node)
 			break;
@@ -300,7 +296,7 @@ static int rcar_du_encoders_init_one(struct
rcar_du_device *rcdu, static int rcar_du_encoders_init(struct
rcar_du_device *rcdu)
 {
 	struct device_node *np = rcdu->dev->of_node;
-	struct device_node *prev = NULL;
+	struct device_node *ep_node = NULL;
 	unsigned int num_encoders = 0;

 	/*
@@ -308,15 +304,12 @@ static int rcar_du_encoders_init(struct rcar_du_device
*rcdu) * pipeline.
 	 */
 	while (1) {
-		struct device_node *ep_node;
 		enum rcar_du_output output;
 		struct of_endpoint ep;
 		unsigned int i;
 		int ret;

-		ep_node = of_graph_get_next_endpoint(np, prev);
-		of_node_put(prev);
-		prev = ep_node;
+		ep_node = of_graph_get_next_endpoint(np, ep_node);

 		if (ep_node == NULL)
 			break;
diff --git a/drivers/media/platform/soc_camera/soc_camera.c
b/drivers/media/platform/soc_camera/soc_camera.c index b3db51c..289b637
100644
--- a/drivers/media/platform/soc_camera/soc_camera.c
+++ b/drivers/media/platform/soc_camera/soc_camera.c
@@ -1710,7 +1710,6 @@ static void scan_of_host(struct soc_camera_host *ici)
 		if (!i)
 			soc_of_bind(ici, epn, ren->parent);

-		of_node_put(epn);
 		of_node_put(ren);

 		if (i) {
@@ -1718,6 +1717,8 @@ static void scan_of_host(struct soc_camera_host *ici)
 			break;
 		}
 	}
+
+	of_node_put(epn);
 }

 #else
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 36536b6..aac66df 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -2085,8 +2085,7 @@ EXPORT_SYMBOL(of_graph_parse_endpoint);
  * @prev: previous endpoint node, or NULL to get first
  *
  * Return: An 'endpoint' node pointer with refcount incremented. Refcount
- * of the passed @prev node is not decremented, the caller have to use
- * of_node_put() on it when done.
+ * of the passed @prev node is decremented.
  */
 struct device_node *of_graph_get_next_endpoint(const struct device_node
*parent, struct device_node *prev)
@@ -2122,12 +2121,6 @@ struct device_node *of_graph_get_next_endpoint(const
struct device_node *parent, if (WARN_ONCE(!port, "%s(): endpoint %s has no
parent node\n",
 			      __func__, prev->full_name))
 			return NULL;
-
-		/*
-		 * Avoid dropping prev node refcount to 0 when getting the next
-		 * child below.
-		 */
-		of_node_get(prev);
 	}

 	while (1) {
diff --git a/drivers/video/fbdev/omap2/dss/omapdss-boot-init.c
b/drivers/video/fbdev/omap2/dss/omapdss-boot-init.c index 2f0822e..76fb18b
100644
--- a/drivers/video/fbdev/omap2/dss/omapdss-boot-init.c
+++ b/drivers/video/fbdev/omap2/dss/omapdss-boot-init.c
@@ -164,20 +164,15 @@ static void __init omapdss_walk_device(struct
device_node *node, bool root)

 		pn = of_graph_get_remote_port_parent(n);

-		if (!pn) {
-			of_node_put(n);
+		if (!pn)
 			continue;
-		}

 		if (!of_device_is_available(pn) || omapdss_list_contains(pn)) {
 			of_node_put(pn);
-			of_node_put(n);
 			continue;
 		}

 		omapdss_walk_device(pn, false);
-
-		of_node_put(n);
 	}
 }
-- 
Regards,

Laurent Pinchart
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