target/linux/generic/pending-4.19/759-net-sfp-re-attempt-probing-for-phy.patch

   1 From 6c4efe83a0acf6f06c89ae17b885fa5739eb5be7 Mon Sep 17 00:00:00 2001
   2 From: Russell King <rmk+kernel@armlinux.org.uk>
   3 Date: Mon, 2 Dec 2019 18:20:22 +0000
   4 Subject: [PATCH 4/4] net: sfp: re-attempt probing for phy
   5
   6 Some 1000BASE-T PHY modules take a while for the PHY to wake up.
   7 Retry the probe a number of times before deciding that the module has
   8 no PHY.
   9
  10 Tested with:
  11  Sourcephotonics SPGBTXCNFC - PHY takes less than 50ms to respond.
  12  Champion One 1000SFPT - PHY takes about 200ms to respond.
  13  Mikrotik S-RJ01 - no PHY
  14
  15 Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
  16 ---
  17  drivers/net/phy/sfp.c | 59 ++++++++++++++++++++++++++++++++++++---------------
  18  1 file changed, 42 insertions(+), 17 deletions(-)
  19
  20 --- a/drivers/net/phy/sfp.c
  21 +++ b/drivers/net/phy/sfp.c
  22 @@ -60,6 +60,7 @@ enum {
  23         SFP_S_FAIL,
  24         SFP_S_WAIT,
  25         SFP_S_INIT,
  26 +       SFP_S_INIT_PHY,
  27         SFP_S_INIT_TX_FAULT,
  28         SFP_S_WAIT_LOS,
  29         SFP_S_LINK_UP,
  30 @@ -124,6 +125,7 @@ static const char * const sm_state_strin
  31         [SFP_S_FAIL] = "fail",
  32         [SFP_S_WAIT] = "wait",
  33         [SFP_S_INIT] = "init",
  34 +       [SFP_S_INIT_PHY] = "init_phy",
  35         [SFP_S_INIT_TX_FAULT] = "init_tx_fault",
  36         [SFP_S_WAIT_LOS] = "wait_los",
  37         [SFP_S_LINK_UP] = "link_up",
  38 @@ -168,6 +170,12 @@ static const enum gpiod_flags gpio_flags
  39  #define N_FAULT_INIT           5
  40  #define N_FAULT                        5
  41
  42 +/* T_PHY_RETRY is the time interval between attempts to probe the PHY.
  43 + * R_PHY_RETRY is the number of attempts.
  44 + */
  45 +#define T_PHY_RETRY            msecs_to_jiffies(50)
  46 +#define R_PHY_RETRY            12
  47 +
  48  /* SFP module presence detection is poor: the three MOD DEF signals are
  49   * the same length on the PCB, which means it's possible for MOD DEF 0 to
  50   * connect before the I2C bus on MOD DEF 1/2.
  51 @@ -223,6 +231,7 @@ struct sfp {
  52         unsigned char sm_dev_state;
  53         unsigned short sm_state;
  54         unsigned char sm_fault_retries;
  55 +       unsigned char sm_phy_retries;
  56
  57         struct sfp_eeprom_id id;
  58         unsigned int module_power_mW;
  59 @@ -1340,10 +1349,8 @@ static int sfp_sm_probe_phy(struct sfp *
  60         int err;
  61
  62         phy = get_phy_device(sfp->i2c_mii, SFP_PHY_ADDR, is_c45);
  63 -       if (phy == ERR_PTR(-ENODEV)) {
  64 -               dev_info(sfp->dev, "no PHY detected\n");
  65 -               return 0;
  66 -       }
  67 +       if (phy == ERR_PTR(-ENODEV))
  68 +               return PTR_ERR(phy);
  69         if (IS_ERR(phy)) {
  70                 dev_err(sfp->dev, "mdiobus scan returned %ld\n", PTR_ERR(phy));
  71                 return PTR_ERR(phy);
  72 @@ -1785,6 +1792,7 @@ static void sfp_sm_module(struct sfp *sf
  73  static void sfp_sm_main(struct sfp *sfp, unsigned int event)
  74  {
  75         unsigned long timeout;
  76 +       int ret;
  77
  78         /* Some events are global */
  79         if (sfp->sm_state != SFP_S_DOWN &&
  80 @@ -1857,22 +1865,39 @@ static void sfp_sm_main(struct sfp *sfp,
  81                         sfp_sm_fault(sfp, SFP_S_INIT_TX_FAULT,
  82                                      sfp->sm_fault_retries == N_FAULT_INIT);
  83                 } else if (event == SFP_E_TIMEOUT || event == SFP_E_TX_CLEAR) {
  84 -       init_done:      /* TX_FAULT deasserted or we timed out with TX_FAULT
  85 -                        * clear.  Probe for the PHY and check the LOS state.
  86 -                        */
  87 -                       if (sfp_sm_probe_for_phy(sfp)) {
  88 -                               sfp_sm_next(sfp, SFP_S_FAIL, 0);
  89 -                               break;
  90 -                       }
  91 -                       if (sfp_module_start(sfp->sfp_bus)) {
  92 -                               sfp_sm_next(sfp, SFP_S_FAIL, 0);
  93 +       init_done:
  94 +                       sfp->sm_phy_retries = R_PHY_RETRY;
  95 +                       goto phy_probe;
  96 +               }
  97 +               break;
  98 +
  99 +       case SFP_S_INIT_PHY:
 100 +               if (event != SFP_E_TIMEOUT)
 101 +                       break;
 102 +       phy_probe:
 103 +               /* TX_FAULT deasserted or we timed out with TX_FAULT
 104 +                * clear.  Probe for the PHY and check the LOS state.
 105 +                */
 106 +               ret = sfp_sm_probe_for_phy(sfp);
 107 +               if (ret == -ENODEV) {
 108 +                       if (--sfp->sm_phy_retries) {
 109 +                               sfp_sm_next(sfp, SFP_S_INIT_PHY, T_PHY_RETRY);
 110                                 break;
 111 +                       } else {
 112 +                               dev_info(sfp->dev, "no PHY detected\n");
 113                         }
 114 -                       sfp_sm_link_check_los(sfp);
 115 -
 116 -                       /* Reset the fault retry count */
 117 -                       sfp->sm_fault_retries = N_FAULT;
 118 +               } else if (ret) {
 119 +                       sfp_sm_next(sfp, SFP_S_FAIL, 0);
 120 +                       break;
 121                 }
 122 +               if (sfp_module_start(sfp->sfp_bus)) {
 123 +                       sfp_sm_next(sfp, SFP_S_FAIL, 0);
 124 +                       break;
 125 +               }
 126 +               sfp_sm_link_check_los(sfp);
 127 +
 128 +               /* Reset the fault retry count */
 129 +               sfp->sm_fault_retries = N_FAULT;
 130                 break;
 131
 132         case SFP_S_INIT_TX_FAULT: