target/linux/generic/backport-5.4/731-v5.5-net-sfp-ensure-TX_FAULT-has-deasserted-before-probin.patch

   1 From 38b62a12231be4b86fc5ca5477579d29831c02a5 Mon Sep 17 00:00:00 2001
   2 From: Russell King <rmk+kernel@armlinux.org.uk>
   3 Date: Fri, 18 Oct 2019 10:31:07 +0100
   4 Subject: [PATCH 629/660] net: sfp: ensure TX_FAULT has deasserted before
   5  probing the PHY
   6
   7 TX_FAULT should be deasserted to indicate that the module has completed
   8 its initialisation.  This may include the on-board PHY, so wait until
   9 the module has deasserted TX_FAULT before probing the PHY.
  10
  11 This means that we need an extra state to handle a TX_FAULT that
  12 remains set for longer than t_init, since using the existing handling
  13 state would bypass the PHY probe.
  14
  15 Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
  16 ---
  17  drivers/net/phy/sfp.c | 31 +++++++++++++++++++++++++------
  18  1 file changed, 25 insertions(+), 6 deletions(-)
  19
  20 --- a/drivers/net/phy/sfp.c
  21 +++ b/drivers/net/phy/sfp.c
  22 @@ -54,6 +54,7 @@ enum {
  23         SFP_S_DOWN = 0,
  24         SFP_S_WAIT,
  25         SFP_S_INIT,
  26 +       SFP_S_INIT_TX_FAULT,
  27         SFP_S_WAIT_LOS,
  28         SFP_S_LINK_UP,
  29         SFP_S_TX_FAULT,
  30 @@ -111,6 +112,7 @@ static const char * const sm_state_strin
  31         [SFP_S_DOWN] = "down",
  32         [SFP_S_WAIT] = "wait",
  33         [SFP_S_INIT] = "init",
  34 +       [SFP_S_INIT_TX_FAULT] = "init_tx_fault",
  35         [SFP_S_WAIT_LOS] = "wait_los",
  36         [SFP_S_LINK_UP] = "link_up",
  37         [SFP_S_TX_FAULT] = "tx_fault",
  38 @@ -1595,8 +1597,6 @@ static void sfp_sm_main(struct sfp *sfp,
  39                 if (event != SFP_E_TIMEOUT)
  40                         break;
  41
  42 -               sfp_sm_probe_for_phy(sfp);
  43 -
  44                 if (sfp->state & SFP_F_TX_FAULT) {
  45                         /* Wait t_init before indicating that the link is up,
  46                          * provided the current state indicates no TX_FAULT. If
  47 @@ -1618,10 +1618,29 @@ static void sfp_sm_main(struct sfp *sfp,
  48                 break;
  49
  50         case SFP_S_INIT:
  51 -               if (event == SFP_E_TIMEOUT && sfp->state & SFP_F_TX_FAULT)
  52 -                       sfp_sm_fault(sfp, SFP_S_TX_FAULT, true);
  53 -               else if (event == SFP_E_TIMEOUT || event == SFP_E_TX_CLEAR)
  54 -       init_done:      sfp_sm_link_check_los(sfp);
  55 +               if (event == SFP_E_TIMEOUT && sfp->state & SFP_F_TX_FAULT) {
  56 +                       /* TX_FAULT is still asserted after t_init, so assume
  57 +                        * there is a fault.
  58 +                        */
  59 +                       sfp_sm_fault(sfp, SFP_S_INIT_TX_FAULT,
  60 +                                    sfp->sm_retries == 5);
  61 +               } else if (event == SFP_E_TIMEOUT || event == SFP_E_TX_CLEAR) {
  62 +       init_done:      /* TX_FAULT deasserted or we timed out with TX_FAULT
  63 +                        * clear.  Probe for the PHY and check the LOS state.
  64 +                        */
  65 +                       sfp_sm_probe_for_phy(sfp);
  66 +                       sfp_sm_link_check_los(sfp);
  67 +
  68 +                       /* Reset the fault retry count */
  69 +                       sfp->sm_retries = 5;
  70 +               }
  71 +               break;
  72 +
  73 +       case SFP_S_INIT_TX_FAULT:
  74 +               if (event == SFP_E_TIMEOUT) {
  75 +                       sfp_module_tx_fault_reset(sfp);
  76 +                       sfp_sm_next(sfp, SFP_S_INIT, T_INIT_JIFFIES);
  77 +               }
  78                 break;
  79
  80         case SFP_S_WAIT_LOS: