net: sfp: split power mode switching from probe

Switch the power mode switching from the probe, so that we don't
repeatedly re-probe the SFP device if there is a problem accessing
the registers at I2C address 0x51.

In splitting this out, we can also fix a bug where we leave the module
in high-power mode when the upstream device is detached but the module
is still inserted.

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 bb4ede83bf5379bb43f51d23edadd6255308423e..66946accb04405f396113e58893e9e63cb72e5d4 100644 (file)
--- a/drivers/net/phy/sfp.c
+++ b/drivers/net/phy/sfp.c
@@ -49,6 +49,7 @@ enum {
        SFP_MOD_EMPTY = 0,
        SFP_MOD_PROBE,
        SFP_MOD_HPOWER,
+       SFP_MOD_WAITPWR,
        SFP_MOD_PRESENT,
        SFP_MOD_ERROR,
 
@@ -71,6 +72,7 @@ static const char  * const mod_state_strings[] = {
        [SFP_MOD_EMPTY] = "empty",
        [SFP_MOD_PROBE] = "probe",
        [SFP_MOD_HPOWER] = "hpower",
+       [SFP_MOD_WAITPWR] = "waitpwr",
        [SFP_MOD_PRESENT] = "present",
        [SFP_MOD_ERROR] = "error",
 };
@@ -1423,37 +1425,34 @@ static int sfp_module_parse_power(struct sfp *sfp)
        return 0;
 }
 
-static int sfp_sm_mod_hpower(struct sfp *sfp)
+static int sfp_sm_mod_hpower(struct sfp *sfp, bool enable)
 {
        u8 val;
        int err;
 
-       if (sfp->module_power_mW <= 1000)
-               return 0;
-
        err = sfp_read(sfp, true, SFP_EXT_STATUS, &val, sizeof(val));
        if (err != sizeof(val)) {
                dev_err(sfp->dev, "Failed to read EEPROM: %d\n", err);
-               err = -EAGAIN;
-               goto err;
+               return -EAGAIN;
        }
 
-       val |= BIT(0);
+       if (enable)
+               val |= BIT(0);
+       else
+               val &= ~BIT(0);
 
        err = sfp_write(sfp, true, SFP_EXT_STATUS, &val, sizeof(val));
        if (err != sizeof(val)) {
                dev_err(sfp->dev, "Failed to write EEPROM: %d\n", err);
-               err = -EAGAIN;
-               goto err;
+               return -EAGAIN;
        }
 
-       dev_info(sfp->dev, "Module switched to %u.%uW power level\n",
-                sfp->module_power_mW / 1000,
-                (sfp->module_power_mW / 100) % 10);
-       return T_HPOWER_LEVEL;
+       if (enable)
+               dev_info(sfp->dev, "Module switched to %u.%uW power level\n",
+                        sfp->module_power_mW / 1000,
+                        (sfp->module_power_mW / 100) % 10);
 
-err:
-       return err;
+       return 0;
 }
 
 static int sfp_sm_mod_probe(struct sfp *sfp)
@@ -1549,7 +1548,7 @@ static int sfp_sm_mod_probe(struct sfp *sfp)
        if (ret < 0)
                return ret;
 
-       return sfp_sm_mod_hpower(sfp);
+       return 0;
 }
 
 static void sfp_sm_mod_remove(struct sfp *sfp)
@@ -1594,13 +1593,22 @@ static void sfp_sm_device(struct sfp *sfp, unsigned int event)
  */
 static void sfp_sm_module(struct sfp *sfp, unsigned int event)
 {
-       /* Handle remove event globally, it resets this state machine.
-        * Also deal with upstream detachment.
-        */
-       if (event == SFP_E_REMOVE || sfp->sm_dev_state < SFP_DEV_DOWN) {
+       int err;
+
+       /* Handle remove event globally, it resets this state machine */
+       if (event == SFP_E_REMOVE) {
                if (sfp->sm_mod_state > SFP_MOD_PROBE)
                        sfp_sm_mod_remove(sfp);
-               if (sfp->sm_mod_state != SFP_MOD_EMPTY)
+               sfp_sm_mod_next(sfp, SFP_MOD_EMPTY, 0);
+               return;
+       }
+
+       /* Handle device detach globally */
+       if (sfp->sm_dev_state < SFP_DEV_DOWN) {
+               if (sfp->module_power_mW > 1000 &&
+                   sfp->sm_mod_state > SFP_MOD_HPOWER)
+                       sfp_sm_mod_hpower(sfp, false);
+               if (sfp->sm_mod_state > SFP_MOD_EMPTY)
                        sfp_sm_mod_next(sfp, SFP_MOD_EMPTY, 0);
                return;
        }
@@ -1612,26 +1620,45 @@ static void sfp_sm_module(struct sfp *sfp, unsigned int event)
                break;
 
        case SFP_MOD_PROBE:
-               if (event == SFP_E_TIMEOUT) {
-                       int val = sfp_sm_mod_probe(sfp);
-
-                       if (val == 0)
-                               sfp_sm_mod_next(sfp, SFP_MOD_PRESENT, 0);
-                       else if (val > 0)
-                               sfp_sm_mod_next(sfp, SFP_MOD_HPOWER, val);
-                       else if (val != -EAGAIN)
-                               sfp_sm_mod_next(sfp, SFP_MOD_ERROR, 0);
-                       else
-                               sfp_sm_set_timer(sfp, T_PROBE_RETRY);
+               if (event != SFP_E_TIMEOUT)
+                       break;
+
+               err = sfp_sm_mod_probe(sfp);
+               if (err == -EAGAIN) {
+                       sfp_sm_set_timer(sfp, T_PROBE_RETRY);
+                       break;
+               }
+               if (err < 0) {
+                       sfp_sm_mod_next(sfp, SFP_MOD_ERROR, 0);
+                       break;
                }
-               break;
 
+               /* If this is a power level 1 module, we are done */
+               if (sfp->module_power_mW <= 1000)
+                       goto insert;
+
+               sfp_sm_mod_next(sfp, SFP_MOD_HPOWER, 0);
+               /* fall through */
        case SFP_MOD_HPOWER:
-               if (event == SFP_E_TIMEOUT) {
-                       sfp_sm_mod_next(sfp, SFP_MOD_PRESENT, 0);
+               /* Enable high power mode */
+               err = sfp_sm_mod_hpower(sfp, true);
+               if (err == 0)
+                       sfp_sm_mod_next(sfp, SFP_MOD_WAITPWR, T_HPOWER_LEVEL);
+               else if (err != -EAGAIN)
+                       sfp_sm_mod_next(sfp, SFP_MOD_ERROR, 0);
+               else
+                       sfp_sm_set_timer(sfp, T_PROBE_RETRY);
+               break;
+
+       case SFP_MOD_WAITPWR:
+               /* Wait for T_HPOWER_LEVEL to time out */
+               if (event != SFP_E_TIMEOUT)
                        break;
-               }
-               /* fallthrough */
+
+       insert:
+               sfp_sm_mod_next(sfp, SFP_MOD_PRESENT, 0);
+               break;
+
        case SFP_MOD_PRESENT:
        case SFP_MOD_ERROR:
                break;