[RFC PATCH 3/3] net: dsa: exit probe if no switch were found

From: Neil Armstrong
Date: Wed Sep 30 2015 - 04:21:47 EST


If no switch were found in dsa_setup_dst, return -ENODEV and
exit the dsa_probe cleanly.

Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
---
net/dsa/dsa.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c
index 0c104af..6ae1ab9 100644
--- a/net/dsa/dsa.c
+++ b/net/dsa/dsa.c
@@ -844,10 +844,11 @@ static inline void dsa_of_remove(struct device *dev)
}
#endif

-static void dsa_setup_dst(struct dsa_switch_tree *dst, struct net_device *dev,
+static int dsa_setup_dst(struct dsa_switch_tree *dst, struct net_device *dev,
struct device *parent, struct dsa_platform_data *pd)
{
int i;
+ unsigned configured = 0;

dst->pd = pd;
dst->master_netdev = dev;
@@ -867,9 +868,17 @@ static void dsa_setup_dst(struct dsa_switch_tree *dst, struct net_device *dev,
dst->ds[i] = ds;
if (ds->drv->poll_link != NULL)
dst->link_poll_needed = 1;
+
+ ++configured;
}

/*
+ * If no switch was found, exit cleanly
+ */
+ if (!configured)
+ return -ENODEV;
+
+ /*
* If we use a tagging format that doesn't have an ethertype
* field, make sure that all packets from this point on get
* sent to the tag format's receive function.
@@ -885,6 +894,8 @@ static void dsa_setup_dst(struct dsa_switch_tree *dst, struct net_device *dev,
dst->link_poll_timer.expires = round_jiffies(jiffies + HZ);
add_timer(&dst->link_poll_timer);
}
+
+ return 0;
}

static int dsa_probe(struct platform_device *pdev)
@@ -934,9 +945,9 @@ static int dsa_probe(struct platform_device *pdev)

platform_set_drvdata(pdev, dst);

- dsa_setup_dst(dst, dev, &pdev->dev, pd);
-
- return 0;
+ ret = dsa_setup_dst(dst, dev, &pdev->dev, pd);
+ if (!ret)
+ return 0;

out:
dsa_of_remove(&pdev->dev);
--
1.9.1
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