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net: dpaa2-mac: move rtnl_lock() only around phylink_{,dis}connect_phy()

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After the introduction of a private mac_lock that serializes access to
priv->mac (and port_priv->mac in the switch), the only remaining purpose
of rtnl_lock() is to satisfy the locking requirements of
phylink_fwnode_phy_connect() and phylink_disconnect_phy().

But the functions these live in, dpaa2_mac_connect() and
dpaa2_mac_disconnect(), have contradictory locking requirements.
While phylink_fwnode_phy_connect() wants rtnl_lock() to be held,
phylink_create() wants it to not be held.

Move the rtnl_lock() from top-level (in the dpaa2-eth and dpaa2-switch
drivers) to only surround the phylink calls that require it, in the
dpaa2-mac library code.

This is possible because dpaa2_mac_connect() and dpaa2_mac_disconnect()
run unlocked, and there isn't any danger of an AB/BA deadlock between
the rtnl_mutex and other private locks.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This commit is contained in:
Vladimir Oltean 2022-11-29 16:12:21 +02:00 committed by Paolo Abeni
parent 3c7f44fa9c
commit 87db82cb61
3 changed files with 5 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
View File

@ -4715,7 +4715,6 @@ static irqreturn_t dpni_irq0_handler_thread(int irq_num, void *arg)
dpaa2_eth_set_mac_addr(netdev_priv(net_dev));
dpaa2_eth_update_tx_fqids(priv);
rtnl_lock();
/* We can avoid locking because the "endpoint changed" IRQ
* handler is the only one who changes priv->mac at runtime,
* so we are not racing with anyone.
@ -4725,7 +4724,6 @@ static irqreturn_t dpni_irq0_handler_thread(int irq_num, void *arg)
dpaa2_eth_disconnect_mac(priv);
else
dpaa2_eth_connect_mac(priv);
rtnl_unlock();
}
return IRQ_HANDLED;
@ -5045,9 +5043,7 @@ 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);

5
drivers/net/ethernet/freescale/dpaa2/dpaa2-mac.c
View File

@ -430,7 +430,9 @@ int dpaa2_mac_connect(struct dpaa2_mac *mac)
}
mac->phylink = phylink;
rtnl_lock();
err = phylink_fwnode_phy_connect(mac->phylink, dpmac_node, 0);
rtnl_unlock();
if (err) {
netdev_err(net_dev, "phylink_fwnode_phy_connect() = %d\n", err);
goto err_phylink_destroy;
@ -448,7 +450,10 @@ err_pcs_destroy:
void dpaa2_mac_disconnect(struct dpaa2_mac *mac)
{
rtnl_lock();
phylink_disconnect_phy(mac->phylink);
rtnl_unlock();
phylink_destroy(mac->phylink);
dpaa2_pcs_destroy(mac);
of_phy_put(mac->serdes_phy);

4
drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
View File

@ -1529,7 +1529,6 @@ static irqreturn_t dpaa2_switch_irq0_handler_thread(int irq_num, void *arg)
}
if (status & DPSW_IRQ_EVENT_ENDPOINT_CHANGED) {
rtnl_lock();
/* We can avoid locking because the "endpoint changed" IRQ
* handler is the only one who changes priv->mac at runtime,
* so we are not racing with anyone.
@ -1539,7 +1538,6 @@ static irqreturn_t dpaa2_switch_irq0_handler_thread(int irq_num, void *arg)
dpaa2_switch_port_disconnect_mac(port_priv);
else
dpaa2_switch_port_connect_mac(port_priv);
rtnl_unlock();
}
out:
@ -2957,9 +2955,7 @@ static void dpaa2_switch_remove_port(struct ethsw_core *ethsw,
{
struct ethsw_port_priv *port_priv = ethsw->ports[port_idx];
rtnl_lock();
dpaa2_switch_port_disconnect_mac(port_priv);
rtnl_unlock();
free_netdev(port_priv->netdev);
ethsw->ports[port_idx] = NULL;
}