[PATCH v6 1/3] of: Decrement refcount of previous endpoint in of_graph_get_next_endpoint

From: Philipp Zabel
Date: Mon Dec 22 2014 - 10:11:54 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>
---
Changes since v5:
- Rebased onto v3.19-rc1
- Added coresight and rcar-du
---
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 ++++-----------
drivers/media/platform/soc_camera/soc_camera.c | 3 ++-
drivers/of/base.c | 9 +--------
5 files changed, 11 insertions(+), 42 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) {
--
2.1.4

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