target/linux/layerscape/patches-5.15/704-dpaa2-eth-do-not-hold-rtnl_lock.patch

   1 From d5af37ae22f0364be9ded773d737dd6e5b207b10 Mon Sep 17 00:00:00 2001
   2 From: Ioana Ciornei <ioana.ciornei@nxp.com>
   3 Date: Thu, 21 Nov 2019 21:15:25 +0200
   4 Subject: [PATCH 3/4] dpaa2-eth: do not hold rtnl_lock on phylink_create() or
   5  _destroy()
   6
   7 The rtnl_lock should not be held when calling phylink_create() or
   8 phylink_destroy() since it leads to the deadlock listed below:
   9
  10 [   18.656576]  rtnl_lock+0x18/0x20
  11 [   18.659798]  sfp_bus_add_upstream+0x28/0x90
  12 [   18.663974]  phylink_create+0x2cc/0x828
  13 [   18.667803]  dpaa2_mac_connect+0x14c/0x2a8
  14 [   18.671890]  dpaa2_eth_connect_mac+0x94/0xd8
  15
  16 Fix this by moving the _lock() and _unlock() calls just outside of
  17 phylink_of_phy_connect() and phylink_disconnect_phy().
  18
  19 Fixes: 719479230893 ("dpaa2-eth: add MAC/PHY support through phylink")
  20 Reported-by: Russell King <linux@armlinux.org.uk>
  21 Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
  22 Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
  23 ---
  24  drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c | 4 ----
  25  drivers/net/ethernet/freescale/dpaa2/dpaa2-mac.c | 4 ++++
  26  2 files changed, 4 insertions(+), 4 deletions(-)
  27
  28 --- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
  29 +++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
  30 @@ -4215,12 +4215,10 @@ static irqreturn_t dpni_irq0_handler_thr
  31                 dpaa2_eth_set_mac_addr(netdev_priv(net_dev));
  32                 dpaa2_eth_update_tx_fqids(priv);
  33
  34 -               rtnl_lock();
  35                 if (dpaa2_eth_has_mac(priv))
  36                         dpaa2_eth_disconnect_mac(priv);
  37                 else
  38                         dpaa2_eth_connect_mac(priv);
  39 -               rtnl_unlock();
  40         }
  41
  42         return IRQ_HANDLED;
  43 @@ -4516,9 +4514,7 @@ static int dpaa2_eth_remove(struct fsl_m
  44  #endif
  45
  46         unregister_netdev(net_dev);
  47 -       rtnl_lock();
  48         dpaa2_eth_disconnect_mac(priv);
  49 -       rtnl_unlock();
  50
  51         dpaa2_eth_dl_port_del(priv);
  52         dpaa2_eth_dl_traps_unregister(priv);
  53 --- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-mac.c
  54 +++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-mac.c
  55 @@ -357,7 +357,9 @@ int dpaa2_mac_connect(struct dpaa2_mac *
  56         if (mac->pcs)
  57                 phylink_set_pcs(mac->phylink, &mac->pcs->pcs);
  58
  59 +       rtnl_lock();
  60         err = phylink_fwnode_phy_connect(mac->phylink, dpmac_node, 0);
  61 +       rtnl_unlock();
  62         if (err) {
  63                 netdev_err(net_dev, "phylink_fwnode_phy_connect() = %d\n", err);
  64                 goto err_phylink_destroy;
  65 @@ -378,7 +380,9 @@ void dpaa2_mac_disconnect(struct dpaa2_m
  66         if (!mac->phylink)
  67                 return;
  68
  69 +       rtnl_lock();
  70         phylink_disconnect_phy(mac->phylink);
  71 +       rtnl_unlock();
  72         phylink_destroy(mac->phylink);
  73         dpaa2_pcs_destroy(mac);
  74  }