[PATCH 2/3] net: Expose some errors generated in net_init

Sean Anderson
2020-09-12T21:45:43Z

net_init does not always succeed, and there is no existing mechanism to
discover errors. This patch allows callers of net_init (such as net_init)
to handle errors. The root issue is that eth_get_dev can fail, but
net_init_loop doesn't expose that. The ideal way to fix eth_get_dev would
be to return an error with ERR_PTR, but there are a lot of callers, and all
of them just check if it's NULL. Another approach would be to change the
signature to something like

int eth_get_dev(struct udevice **pdev)

but that would require rewriting all of the many callers.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
---

include/net.h | 2 +-
net/eth-uclass.c | 3 +++
net/net.c | 15 +++++++++++----
3 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/include/net.h b/include/net.h
index 1bf9867f8c..b80b13ae7c 100644
--- a/include/net.h
+++ b/include/net.h
@@ -593,7 +593,7 @@ extern int net_ntp_time_offset; /* offset time from UTC */
#endif

/* Initialize the network adapter */
-void net_init(void);
+int net_init(void);
int net_loop(enum proto_t);

/* Load failed. Start again. */
diff --git a/net/eth-uclass.c b/net/eth-uclass.c
index 0d9b75a9a2..1f59d24f54 100644
--- a/net/eth-uclass.c
+++ b/net/eth-uclass.c
@@ -75,6 +75,9 @@ struct udevice *eth_get_dev(void)
struct eth_uclass_priv *uc_priv;

uc_priv = eth_get_uclass_priv();
+ if (!uc_priv)
+ return NULL;
+
if (!uc_priv->current)
eth_errno = uclass_first_device(UCLASS_ETH,
&uc_priv->current);
diff --git a/net/net.c b/net/net.c
index 28d9eebf9d..3afd0d6fb0 100644
--- a/net/net.c
+++ b/net/net.c
@@ -353,12 +353,19 @@ void net_auto_load(void)
tftp_start(TFTPGET);
}

-static void net_init_loop(void)
+static int net_init_loop(void)
{
if (eth_get_dev())
memcpy(net_ethaddr, eth_get_ethaddr(), 6);
+ else
+ /*
+ * Not ideal, but there's no way to get the actual error, and I
+ * don't feel like fixing all the users of eth_get_dev to deal
+ * with errors.
+ */
+ return -ENONET;

- return;
+ return 0;
}

static void net_clear_handlers(void)
@@ -373,7 +380,7 @@ static void net_cleanup_loop(void)
net_clear_handlers();
}

-void net_init(void)
+int net_init(void)
{
static int first_call = 1;

@@ -396,7 +403,7 @@ void net_init(void)
first_call = 0;
}

- net_init_loop();
+ return net_init_loop();
}

/**********************************************************************/
--
2.28.0