target/linux/generic/backport-5.4/715-v5.3-net-phylink-don-t-start-and-stop-SGMII-PHYs-in-SFP-m.patch

   1 From b8803113537a1c1f457eba6270d46e3af305031f Mon Sep 17 00:00:00 2001
   2 From: Arseny Solokha <asolokha@kb.kras.ru>
   3 Date: Wed, 24 Jul 2019 20:31:39 +0700
   4 Subject: [PATCH 613/660] net: phylink: don't start and stop SGMII PHYs in SFP
   5  modules twice
   6
   7 SFP modules connected using the SGMII interface have their own PHYs which
   8 are handled by the struct phylink's phydev field. On the other hand, for
   9 the modules connected using 1000Base-X interface that field is not set.
  10
  11 Since commit ce0aa27ff3f6 ("sfp: add sfp-bus to bridge between network
  12 devices and sfp cages") phylink_start() ends up setting the phydev field
  13 using the sfp-bus infrastructure, which eventually calls phy_start() on it,
  14 and then calling phy_start() again on the same phydev from phylink_start()
  15 itself. Similar call sequence holds for phylink_stop(), only in the reverse
  16 order. This results in WARNs during network interface bringup and shutdown
  17 when a copper SFP module is connected, as phy_start() and phy_stop() are
  18 called twice in a row for the same phy_device:
  19
  20   % ip link set up dev eth0
  21   ------------[ cut here ]------------
  22   called from state UP
  23   WARNING: CPU: 1 PID: 155 at drivers/net/phy/phy.c:895 phy_start+0x74/0xc0
  24   Modules linked in:
  25   CPU: 1 PID: 155 Comm: backend Not tainted 5.2.0+ #1
  26   NIP:  c0227bf0 LR: c0227bf0 CTR: c004d224
  27   REGS: df547720 TRAP: 0700   Not tainted  (5.2.0+)
  28   MSR:  00029000 <CE,EE,ME>  CR: 24002822  XER: 00000000
  29
  30   GPR00: c0227bf0 df5477d8 df5d7080 00000014 df9d2370 df9d5ac4 1f4eb000 00000001
  31   GPR08: c061fe58 00000000 00000000 df5477d8 0000003c 100c8768 00000000 00000000
  32   GPR16: df486a00 c046f1c8 c046eea0 00000000 c046e904 c0239604 db68449c 00000000
  33   GPR24: e9083204 00000000 00000001 db684460 e9083404 00000000 db6dce00 db6dcc00
  34   NIP [c0227bf0] phy_start+0x74/0xc0
  35   LR [c0227bf0] phy_start+0x74/0xc0
  36   Call Trace:
  37   [df5477d8] [c0227bf0] phy_start+0x74/0xc0 (unreliable)
  38   [df5477e8] [c023cad0] startup_gfar+0x398/0x3f4
  39   [df547828] [c023cf08] gfar_enet_open+0x364/0x374
  40   [df547898] [c029d870] __dev_open+0xe4/0x140
  41   [df5478c8] [c029db70] __dev_change_flags+0xf0/0x188
  42   [df5478f8] [c029dc28] dev_change_flags+0x20/0x54
  43   [df547918] [c02ae304] do_setlink+0x310/0x818
  44   [df547a08] [c02b1eb8] __rtnl_newlink+0x384/0x6b0
  45   [df547c28] [c02b222c] rtnl_newlink+0x48/0x68
  46   [df547c48] [c02ad7c8] rtnetlink_rcv_msg+0x240/0x27c
  47   [df547c98] [c02cc068] netlink_rcv_skb+0x8c/0xf0
  48   [df547cd8] [c02cba3c] netlink_unicast+0x114/0x19c
  49   [df547d08] [c02cbd74] netlink_sendmsg+0x2b0/0x2c0
  50   [df547d58] [c027b668] sock_sendmsg_nosec+0x20/0x40
  51   [df547d68] [c027d080] ___sys_sendmsg+0x17c/0x1dc
  52   [df547e98] [c027df7c] __sys_sendmsg+0x68/0x84
  53   [df547ef8] [c027e430] sys_socketcall+0x1a0/0x204
  54   [df547f38] [c000d1d8] ret_from_syscall+0x0/0x38
  55   --- interrupt: c01 at 0xfd4e030
  56       LR = 0xfd4e010
  57   Instruction dump:
  58   813f0188 38800000 2b890005 419d0014 3d40c046 5529103a 394aa208 7c8a482e
  59   3c60c046 3863a1b8 4cc63182 4be009a1 <0fe00000> 48000030 3c60c046 3863a1d0
  60   ---[ end trace d4c095aeaf6ea998 ]---
  61
  62 and
  63
  64   % ip link set down dev eth0
  65   ------------[ cut here ]------------
  66   called from state HALTED
  67   WARNING: CPU: 1 PID: 184 at drivers/net/phy/phy.c:858 phy_stop+0x3c/0x88
  68
  69   <...>
  70
  71   Call Trace:
  72   [df581788] [c0228450] phy_stop+0x3c/0x88 (unreliable)
  73   [df581798] [c022d548] sfp_sm_phy_detach+0x1c/0x44
  74   [df5817a8] [c022e8cc] sfp_sm_event+0x4b0/0x87c
  75   [df581848] [c022f04c] sfp_upstream_stop+0x34/0x44
  76   [df581858] [c0225608] phylink_stop+0x7c/0xe4
  77   [df581868] [c023c57c] stop_gfar+0x7c/0x94
  78   [df581888] [c023c5b8] gfar_close+0x24/0x94
  79   [df5818a8] [c0298688] __dev_close_many+0xdc/0xf8
  80   [df5818c8] [c029db58] __dev_change_flags+0xd8/0x188
  81   [df5818f8] [c029dc28] dev_change_flags+0x20/0x54
  82   [df581918] [c02ae304] do_setlink+0x310/0x818
  83   [df581a08] [c02b1eb8] __rtnl_newlink+0x384/0x6b0
  84   [df581c28] [c02b222c] rtnl_newlink+0x48/0x68
  85   [df581c48] [c02ad7c8] rtnetlink_rcv_msg+0x240/0x27c
  86   [df581c98] [c02cc068] netlink_rcv_skb+0x8c/0xf0
  87   [df581cd8] [c02cba3c] netlink_unicast+0x114/0x19c
  88   [df581d08] [c02cbd74] netlink_sendmsg+0x2b0/0x2c0
  89   [df581d58] [c027b668] sock_sendmsg_nosec+0x20/0x40
  90   [df581d68] [c027d080] ___sys_sendmsg+0x17c/0x1dc
  91   [df581e98] [c027df7c] __sys_sendmsg+0x68/0x84
  92   [df581ef8] [c027e430] sys_socketcall+0x1a0/0x204
  93   [df581f38] [c000d1d8] ret_from_syscall+0x0/0x38
  94
  95   <...>
  96
  97   ---[ end trace d4c095aeaf6ea999 ]---
  98
  99 SFP modules with the 1000Base-X interface are not affected.
 100
 101 Place explicit calls to phy_start() and phy_stop() before enabling or after
 102 disabling an attached SFP module, where phydev is not yet set (or is
 103 already unset), so they will be made only from the inside of sfp-bus, if
 104 needed.
 105
 106 Fixes: 217962615662 ("net: phy: warn if phy_start is called from invalid state")
 107 Signed-off-by: Arseny Solokha <asolokha@kb.kras.ru>
 108 Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
 109 Signed-off-by: David S. Miller <davem@davemloft.net>
 110 ---
 111  drivers/net/phy/phylink.c | 8 ++++----
 112  1 file changed, 4 insertions(+), 4 deletions(-)
 113
 114 --- a/drivers/net/phy/phylink.c
 115 +++ b/drivers/net/phy/phylink.c
 116 @@ -973,10 +973,10 @@ void phylink_start(struct phylink *pl)
 117         }
 118         if (pl->link_an_mode == MLO_AN_FIXED && pl->get_fixed_state)
 119                 mod_timer(&pl->link_poll, jiffies + HZ);
 120 -       if (pl->sfp_bus)
 121 -               sfp_upstream_start(pl->sfp_bus);
 122         if (pl->phydev)
 123                 phy_start(pl->phydev);
 124 +       if (pl->sfp_bus)
 125 +               sfp_upstream_start(pl->sfp_bus);
 126  }
 127  EXPORT_SYMBOL_GPL(phylink_start);
 128
 129 @@ -993,10 +993,10 @@ void phylink_stop(struct phylink *pl)
 130  {
 131         ASSERT_RTNL();
 132
 133 -       if (pl->phydev)
 134 -               phy_stop(pl->phydev);
 135         if (pl->sfp_bus)
 136                 sfp_upstream_stop(pl->sfp_bus);
 137 +       if (pl->phydev)
 138 +               phy_stop(pl->phydev);
 139         del_timer_sync(&pl->link_poll);
 140         if (pl->link_irq) {
 141                 free_irq(pl->link_irq, pl);