target/linux/generic/pending-5.4/739-net-avoid-tx-fault-with-Nokia-GPON-module.patch

   1 From 283b211aa01bdae94dffb3121655dbb20bf237f4 Mon Sep 17 00:00:00 2001
   2 From: Russell King <rmk+kernel@armlinux.org.uk>
   3 Date: Tue, 3 Dec 2019 15:22:05 +0000
   4 Subject: net: sfp: avoid tx-fault with Nokia GPON module
   5
   6 The Nokia GPON module can hold tx-fault active while it is initialising
   7 which can take up to 60s. Avoid this causing the module to be declared
   8 faulty after the SFP MSA defined non-cooled module timeout.
   9
  10 Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
  11 ---
  12  drivers/net/phy/sfp.c | 42 ++++++++++++++++++++++++++++++------------
  13  1 file changed, 30 insertions(+), 12 deletions(-)
  14
  15 --- a/drivers/net/phy/sfp.c
  16 +++ b/drivers/net/phy/sfp.c
  17 @@ -153,10 +153,20 @@ static const enum gpiod_flags gpio_flags
  18         GPIOD_ASIS,
  19  };
  20
  21 -#define T_WAIT         msecs_to_jiffies(50)
  22 -#define T_INIT_JIFFIES msecs_to_jiffies(300)
  23 -#define T_RESET_US     10
  24 -#define T_FAULT_RECOVER        msecs_to_jiffies(1000)
  25 +/* t_start_up (SFF-8431) or t_init (SFF-8472) is the time required for a
  26 + * non-cooled module to initialise its laser safety circuitry. We wait
  27 + * an initial T_WAIT period before we check the tx fault to give any PHY
  28 + * on board (for a copper SFP) time to initialise.
  29 + */
  30 +#define T_WAIT                 msecs_to_jiffies(50)
  31 +#define T_START_UP             msecs_to_jiffies(300)
  32 +#define T_START_UP_BAD_GPON    msecs_to_jiffies(60000)
  33 +
  34 +/* t_reset is the time required to assert the TX_DISABLE signal to reset
  35 + * an indicated TX_FAULT.
  36 + */
  37 +#define T_RESET_US             10
  38 +#define T_FAULT_RECOVER                msecs_to_jiffies(1000)
  39
  40  /* SFP module presence detection is poor: the three MOD DEF signals are
  41   * the same length on the PCB, which means it's possible for MOD DEF 0 to
  42 @@ -216,6 +226,7 @@ struct sfp {
  43
  44         struct sfp_eeprom_id id;
  45         unsigned int module_power_mW;
  46 +       unsigned int module_t_start_up;
  47
  48  #if IS_ENABLED(CONFIG_HWMON)
  49         struct sfp_diag diag;
  50 @@ -1590,6 +1601,12 @@ static int sfp_sm_mod_probe(struct sfp *
  51         if (ret < 0)
  52                 return ret;
  53
  54 +       if (!memcmp(id.base.vendor_name, "ALCATELLUCENT   ", 16) &&
  55 +           !memcmp(id.base.vendor_pn, "3FE46541AA      ", 16))
  56 +               sfp->module_t_start_up = T_START_UP_BAD_GPON;
  57 +       else
  58 +               sfp->module_t_start_up = T_START_UP;
  59 +
  60         return 0;
  61  }
  62
  63 @@ -1795,11 +1812,12 @@ static void sfp_sm_main(struct sfp *sfp,
  64                         break;
  65
  66                 if (sfp->state & SFP_F_TX_FAULT) {
  67 -                       /* Wait t_init before indicating that the link is up,
  68 -                        * provided the current state indicates no TX_FAULT. If
  69 -                        * TX_FAULT clears before this time, that's fine too.
  70 +                       /* Wait up to t_init (SFF-8472) or t_start_up (SFF-8431)
  71 +                        * from the TX_DISABLE deassertion for the module to
  72 +                        * initialise, which is indicated by TX_FAULT
  73 +                        * deasserting.
  74                          */
  75 -                       timeout = T_INIT_JIFFIES;
  76 +                       timeout = sfp->module_t_start_up;
  77                         if (timeout > T_WAIT)
  78                                 timeout -= T_WAIT;
  79                         else
  80 @@ -1816,8 +1834,8 @@ static void sfp_sm_main(struct sfp *sfp,
  81
  82         case SFP_S_INIT:
  83                 if (event == SFP_E_TIMEOUT && sfp->state & SFP_F_TX_FAULT) {
  84 -                       /* TX_FAULT is still asserted after t_init, so assume
  85 -                        * there is a fault.
  86 +                       /* TX_FAULT is still asserted after t_init or
  87 +                        * or t_start_up, so assume there is a fault.
  88                          */
  89                         sfp_sm_fault(sfp, SFP_S_INIT_TX_FAULT,
  90                                      sfp->sm_retries == 5);
  91 @@ -1836,7 +1854,7 @@ static void sfp_sm_main(struct sfp *sfp,
  92         case SFP_S_INIT_TX_FAULT:
  93                 if (event == SFP_E_TIMEOUT) {
  94                         sfp_module_tx_fault_reset(sfp);
  95 -                       sfp_sm_next(sfp, SFP_S_INIT, T_INIT_JIFFIES);
  96 +                       sfp_sm_next(sfp, SFP_S_INIT, sfp->module_t_start_up);
  97                 }
  98                 break;
  99
 100 @@ -1860,7 +1878,7 @@ static void sfp_sm_main(struct sfp *sfp,
 101         case SFP_S_TX_FAULT:
 102                 if (event == SFP_E_TIMEOUT) {
 103                         sfp_module_tx_fault_reset(sfp);
 104 -                       sfp_sm_next(sfp, SFP_S_REINIT, T_INIT_JIFFIES);
 105 +                       sfp_sm_next(sfp, SFP_S_REINIT, sfp->module_t_start_up);
 106                 }
 107                 break;
 108