[PATCH] net: stmmac: manage errors returned by of_get_mac_address()

Martin Blumenstingl martin.blumenstingl at googlemail.com
Sat Jul 27 12:21:37 PDT 2019

Commit d01f449c008a ("of_net: add NVMEM support to of_get_mac_address")
added support for reading the MAC address from an nvmem-cell. This
required changing the logic to return an error pointer upon failure.

If stmmac is loaded before the nvmem provider driver then
of_get_mac_address() return an error pointer with -EPROBE_DEFER.

Propagate this error so the stmmac driver will be probed again after the
nvmem provider driver is loaded.
Default to a random generated MAC address in case of any other error,
instead of using the error pointer as MAC address.

Fixes: d01f449c008a ("of_net: add NVMEM support to of_get_mac_address")
Signed-off-by: Martin Blumenstingl <martin.blumenstingl at googlemail.com>
 drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
index 73fc2524372e..154daf4d1072 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
@@ -370,6 +370,13 @@ stmmac_probe_config_dt(struct platform_device *pdev, const char **mac)
 		return ERR_PTR(-ENOMEM);
 	*mac = of_get_mac_address(np);
+	if (IS_ERR(*mac)) {
+		if (PTR_ERR(*mac) == -EPROBE_DEFER)
+			return ERR_CAST(*mac);
+		*mac = NULL;
+	}
 	plat->interface = of_get_phy_mode(np);
 	/* Some wrapper drivers still rely on phy_node. Let's save it while

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