net: sfp: ensure TX_FAULT has deasserted before probing the PHY

TX_FAULT should be deasserted to indicate that the module has completed
its initialisation.  This may include the on-board PHY, so wait until
the module has deasserted TX_FAULT before probing the PHY.

This means that we need an extra state to handle a TX_FAULT that
remains set for longer than t_init, since using the existing handling
state would bypass the PHY probe.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c
index 72c6776c1ce6091e3bd8edc08e28be010e449168..cb0a35b1bb71f5752977c366cc8e969c313ec4ba 100644 (file)
--- a/drivers/net/phy/sfp.c
+++ b/drivers/net/phy/sfp.c
@@ -56,6 +56,7 @@ enum {
        SFP_S_DOWN = 0,
        SFP_S_WAIT,
        SFP_S_INIT,
+       SFP_S_INIT_TX_FAULT,
        SFP_S_WAIT_LOS,
        SFP_S_LINK_UP,
        SFP_S_TX_FAULT,
@@ -113,6 +114,7 @@ static const char * const sm_state_strings[] = {
        [SFP_S_DOWN] = "down",
        [SFP_S_WAIT] = "wait",
        [SFP_S_INIT] = "init",
+       [SFP_S_INIT_TX_FAULT] = "init_tx_fault",
        [SFP_S_WAIT_LOS] = "wait_los",
        [SFP_S_LINK_UP] = "link_up",
        [SFP_S_TX_FAULT] = "tx_fault",
@@ -1660,8 +1662,6 @@ static void sfp_sm_main(struct sfp *sfp, unsigned int event)
                if (event != SFP_E_TIMEOUT)
                        break;
 
-               sfp_sm_probe_for_phy(sfp);
-
                if (sfp->state & SFP_F_TX_FAULT) {
                        /* Wait t_init before indicating that the link is up,
                         * provided the current state indicates no TX_FAULT. If
@@ -1683,10 +1683,29 @@ static void sfp_sm_main(struct sfp *sfp, unsigned int event)
                break;
 
        case SFP_S_INIT:
-               if (event == SFP_E_TIMEOUT && sfp->state & SFP_F_TX_FAULT)
-                       sfp_sm_fault(sfp, SFP_S_TX_FAULT, true);
-               else if (event == SFP_E_TIMEOUT || event == SFP_E_TX_CLEAR)
-       init_done:      sfp_sm_link_check_los(sfp);
+               if (event == SFP_E_TIMEOUT && sfp->state & SFP_F_TX_FAULT) {
+                       /* TX_FAULT is still asserted after t_init, so assume
+                        * there is a fault.
+                        */
+                       sfp_sm_fault(sfp, SFP_S_INIT_TX_FAULT,
+                                    sfp->sm_retries == 5);
+               } else if (event == SFP_E_TIMEOUT || event == SFP_E_TX_CLEAR) {
+       init_done:      /* TX_FAULT deasserted or we timed out with TX_FAULT
+                        * clear.  Probe for the PHY and check the LOS state.
+                        */
+                       sfp_sm_probe_for_phy(sfp);
+                       sfp_sm_link_check_los(sfp);
+
+                       /* Reset the fault retry count */
+                       sfp->sm_retries = 5;
+               }
+               break;
+
+       case SFP_S_INIT_TX_FAULT:
+               if (event == SFP_E_TIMEOUT) {
+                       sfp_module_tx_fault_reset(sfp);
+                       sfp_sm_next(sfp, SFP_S_INIT, T_INIT_JIFFIES);
+               }
                break;
 
        case SFP_S_WAIT_LOS: