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net: sfp: re-attempt probing for phy

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Some 1000BASE-T PHY modules take a while for the PHY to wake up.
Retry the probe a number of times before deciding that the module has
no PHY.

Tested with:
 Sourcephotonics SPGBTXCNFC - PHY takes less than 50ms to respond.
 Champion One 1000SFPT - PHY takes about 200ms to respond.
 Mikrotik S-RJ01 - no PHY

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Russell King 2019-12-09 14:16:11 +00:00 committed by David S. Miller
parent 256e43cb8c
commit 1cb89a14c8
1 changed files with 44 additions and 19 deletions

63
drivers/net/phy/sfp.c
View File

@ -62,6 +62,7 @@ enum {
SFP_S_FAIL,
SFP_S_WAIT,
SFP_S_INIT,
SFP_S_INIT_PHY,
SFP_S_INIT_TX_FAULT,
SFP_S_WAIT_LOS,
SFP_S_LINK_UP,
@ -126,6 +127,7 @@ static const char * const sm_state_strings[] = {
[SFP_S_FAIL] = "fail",
[SFP_S_WAIT] = "wait",
[SFP_S_INIT] = "init",
[SFP_S_INIT_PHY] = "init_phy",
[SFP_S_INIT_TX_FAULT] = "init_tx_fault",
[SFP_S_WAIT_LOS] = "wait_los",
[SFP_S_LINK_UP] = "link_up",
@ -180,6 +182,12 @@ static const enum gpiod_flags gpio_flags[] = {
#define N_FAULT_INIT 5
#define N_FAULT 5
/* T_PHY_RETRY is the time interval between attempts to probe the PHY.
* R_PHY_RETRY is the number of attempts.
*/
#define T_PHY_RETRY msecs_to_jiffies(50)
#define R_PHY_RETRY 12
/* SFP module presence detection is poor: the three MOD DEF signals are
* the same length on the PCB, which means it's possible for MOD DEF 0 to
* connect before the I2C bus on MOD DEF 1/2.
@ -235,6 +243,7 @@ struct sfp {
unsigned char sm_dev_state;
unsigned short sm_state;
unsigned char sm_fault_retries;
unsigned char sm_phy_retries;
struct sfp_eeprom_id id;
unsigned int module_power_mW;
@ -1416,10 +1425,8 @@ static int sfp_sm_probe_phy(struct sfp *sfp, bool is_c45)
int err;
phy = get_phy_device(sfp->i2c_mii, SFP_PHY_ADDR, is_c45);
if (phy == ERR_PTR(-ENODEV)) {
dev_info(sfp->dev, "no PHY detected\n");
return 0;
}
if (phy == ERR_PTR(-ENODEV))
return PTR_ERR(phy);
if (IS_ERR(phy)) {
dev_err(sfp->dev, "mdiobus scan returned %ld\n", PTR_ERR(phy));
return PTR_ERR(phy);
@ -1867,6 +1874,7 @@ static void sfp_sm_module(struct sfp *sfp, unsigned int event)
static void sfp_sm_main(struct sfp *sfp, unsigned int event)
{
unsigned long timeout;
int ret;
/* Some events are global */
if (sfp->sm_state != SFP_S_DOWN &&
@ -1940,24 +1948,41 @@ static void sfp_sm_main(struct sfp *sfp, unsigned int event)
sfp_sm_fault(sfp, SFP_S_INIT_TX_FAULT,
sfp->sm_fault_retries == N_FAULT_INIT);
} 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.
*/
if (sfp_sm_probe_for_phy(sfp)) {
sfp_sm_next(sfp, SFP_S_FAIL, 0);
break;
}
if (sfp_module_start(sfp->sfp_bus)) {
sfp_sm_next(sfp, SFP_S_FAIL, 0);
break;
}
sfp_sm_link_check_los(sfp);
/* Reset the fault retry count */
sfp->sm_fault_retries = N_FAULT;
init_done:
sfp->sm_phy_retries = R_PHY_RETRY;
goto phy_probe;
}
break;
case SFP_S_INIT_PHY:
if (event != SFP_E_TIMEOUT)
break;
phy_probe:
/* TX_FAULT deasserted or we timed out with TX_FAULT
* clear. Probe for the PHY and check the LOS state.
*/
ret = sfp_sm_probe_for_phy(sfp);
if (ret == -ENODEV) {
if (--sfp->sm_phy_retries) {
sfp_sm_next(sfp, SFP_S_INIT_PHY, T_PHY_RETRY);
break;
} else {
dev_info(sfp->dev, "no PHY detected\n");
}
} else if (ret) {
sfp_sm_next(sfp, SFP_S_FAIL, 0);
break;
}
if (sfp_module_start(sfp->sfp_bus)) {
sfp_sm_next(sfp, SFP_S_FAIL, 0);
break;
}
sfp_sm_link_check_los(sfp);
/* Reset the fault retry count */
sfp->sm_fault_retries = N_FAULT;
break;
case SFP_S_INIT_TX_FAULT:
if (event == SFP_E_TIMEOUT) {
sfp_module_tx_fault_reset(sfp);