[PATCH net-next 09/12] net: dpaa2-eth: connect to MAC before requesting the "endpoint changed" IRQ

From: Vladimir Oltean
Date: Tue Nov 29 2022 - 09:14:30 EST


dpaa2_eth_connect_mac() is called both from dpaa2_eth_probe() and from
dpni_irq0_handler_thread().

It could happen that the DPNI gets connected to a DPMAC on the fsl-mc
bus exactly during probe, as soon as the "endpoint change" interrupt is
requested in dpaa2_eth_setup_irqs(). This will cause the
dpni_irq0_handler_thread() to register a phylink instance for that DPMAC.

Then, the probing function will also try to register a phylink instance
for the same DPMAC, operation which should fail (and this will fail the
probing of the driver).

Reorder dpaa2_eth_setup_irqs() and dpaa2_eth_connect_mac(), such that
dpni_irq0_handler_thread() never races with the DPMAC-related portion of
the probing path.

Also reorder dpaa2_eth_disconnect_mac() to be in the mirror position of
dpaa2_eth_connect_mac() in the teardown path.

Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
---
.../net/ethernet/freescale/dpaa2/dpaa2-eth.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
index 4dbf8a1651cd..b77d292cd960 100644
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
@@ -4899,6 +4899,10 @@ static int dpaa2_eth_probe(struct fsl_mc_device *dpni_dev)
}
#endif

+ err = dpaa2_eth_connect_mac(priv);
+ if (err)
+ goto err_connect_mac;
+
err = dpaa2_eth_setup_irqs(dpni_dev);
if (err) {
netdev_warn(net_dev, "Failed to set link interrupt, fall back to polling\n");
@@ -4911,10 +4915,6 @@ static int dpaa2_eth_probe(struct fsl_mc_device *dpni_dev)
priv->do_link_poll = true;
}

- err = dpaa2_eth_connect_mac(priv);
- if (err)
- goto err_connect_mac;
-
err = dpaa2_eth_dl_alloc(priv);
if (err)
goto err_dl_register;
@@ -4948,13 +4948,13 @@ static int dpaa2_eth_probe(struct fsl_mc_device *dpni_dev)
err_dl_trap_register:
dpaa2_eth_dl_free(priv);
err_dl_register:
- dpaa2_eth_disconnect_mac(priv);
-err_connect_mac:
if (priv->do_link_poll)
kthread_stop(priv->poll_thread);
else
fsl_mc_free_irqs(dpni_dev);
err_poll_thread:
+ dpaa2_eth_disconnect_mac(priv);
+err_connect_mac:
dpaa2_eth_free_rings(priv);
err_alloc_rings:
err_csum:
@@ -5002,9 +5002,6 @@ static int dpaa2_eth_remove(struct fsl_mc_device *ls_dev)
#endif

unregister_netdev(net_dev);
- rtnl_lock();
- dpaa2_eth_disconnect_mac(priv);
- rtnl_unlock();

dpaa2_eth_dl_port_del(priv);
dpaa2_eth_dl_traps_unregister(priv);
@@ -5015,6 +5012,9 @@ static int dpaa2_eth_remove(struct fsl_mc_device *ls_dev)
else
fsl_mc_free_irqs(ls_dev);

+ rtnl_lock();
+ dpaa2_eth_disconnect_mac(priv);
+ rtnl_unlock();
dpaa2_eth_free_rings(priv);
free_percpu(priv->fd);
free_percpu(priv->sgt_cache);
--
2.34.1