[PATCH v8 1/3] of: Decrement refcount of previous endpoint in of_graph_get_next_endpoint

From: Philipp Zabel
Date: Mon Feb 23 2015 - 05:54:35 EST


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
(that is, soc_camera and imx-drm) are changed to not decrement the passed
prev argument's refcount themselves.

Signed-off-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
Acked-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx>
Acked-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Acked-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Acked-by: Tomi Valkeinen <tomi.valkeinen@xxxxxx>
---
Changes since v7:
- Rebased onto v4.0-rc1
- Added fix for am437x-vpfe
---
drivers/coresight/of_coresight.c | 13 ++-----------
drivers/gpu/drm/imx/imx-drm-core.c | 11 +----------
drivers/gpu/drm/rcar-du/rcar_du_kms.c | 15 ++++-----------
drivers/media/platform/am437x/am437x-vpfe.c | 1 -
drivers/media/platform/soc_camera/soc_camera.c | 3 ++-
drivers/of/base.c | 9 +--------
drivers/video/fbdev/omap2/dss/omapdss-boot-init.c | 7 +------
7 files changed, 11 insertions(+), 48 deletions(-)

diff --git a/drivers/coresight/of_coresight.c b/drivers/coresight/of_coresight.c
index c3efa41..6f75e9d 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 a002f53..84cf99f 100644
--- a/drivers/gpu/drm/imx/imx-drm-core.c
+++ b/drivers/gpu/drm/imx/imx-drm-core.c
@@ -431,15 +431,6 @@ int imx_drm_encoder_parse_of(struct drm_device *drm,
}
EXPORT_SYMBOL_GPL(imx_drm_encoder_parse_of);

-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;
-}
-
/*
* @node: device tree node containing encoder input ports
* @encoder: drm_encoder
@@ -457,7 +448,7 @@ 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 cc9136e..68dab26 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/am437x/am437x-vpfe.c b/drivers/media/platform/am437x/am437x-vpfe.c
index 56a5cb0..0d07fca 100644
--- a/drivers/media/platform/am437x/am437x-vpfe.c
+++ b/drivers/media/platform/am437x/am437x-vpfe.c
@@ -2504,7 +2504,6 @@ vpfe_get_pdata(struct platform_device *pdev)
GFP_KERNEL);
pdata->asd[i]->match_type = V4L2_ASYNC_MATCH_OF;
pdata->asd[i]->match.of.node = rem;
- of_node_put(endpoint);
of_node_put(rem);
}

diff --git a/drivers/media/platform/soc_camera/soc_camera.c b/drivers/media/platform/soc_camera/soc_camera.c
index cee7b56..f2a3d96 100644
--- a/drivers/media/platform/soc_camera/soc_camera.c
+++ b/drivers/media/platform/soc_camera/soc_camera.c
@@ -1694,7 +1694,6 @@ 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) {
@@ -1702,6 +1701,8 @@ 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 0a8aeb8..05b20f1 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -2086,8 +2086,7 @@ 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)
@@ -2123,12 +2122,6 @@ 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 42b87f9..8b6f6d5 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);
}
}

--
2.1.4

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