Commit 2f3ce7a5 authored by Marek Behún's avatar Marek Behún Committed by David S. Miller
Browse files

net: sfp: rework the RollBall PHY waiting code 



RollBall SFP modules allow the access to PHY registers only after a
certain time has passed. Until then, the registers read 0xffff.

Currently we have quirks for modules where we need to wait either 25
seconds or 4 seconds, but recently I got hands on another module where
the wait is even shorter.

Instead of hardcoding different wait times, lets rework the code:
- increase the PHY retry count to 25
- when RollBall module is detected, increase the PHY retry time from
  50ms to 1s

Signed-off-by: default avatarMarek Behún <kabel@kernel.org>
Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 53775da0

drivers/net/phy/sfp.c

+21 −20
Original line number Diff line number Diff line
@@ -191,7 +191,7 @@ static const enum gpiod_flags gpio_flags[] = { 
 * R_PHY_RETRY is the number of attempts.

 */

#define T_PHY_RETRY		msecs_to_jiffies(50)

#define R_PHY_RETRY		12

#define R_PHY_RETRY		25



/* 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
@@ -274,7 +274,7 @@ struct sfp { 
	struct sfp_eeprom_id id;

	unsigned int module_power_mW;

	unsigned int module_t_start_up;

	unsigned int module_t_wait;

	unsigned int phy_t_retry;



	unsigned int rate_kbd;

	unsigned int rs_threshold_kbd;
@@ -372,18 +372,22 @@ static void sfp_fixup_10gbaset_30m(struct sfp *sfp) 
	sfp->id.base.extended_cc = SFF8024_ECC_10GBASE_T_SR;

}



static void sfp_fixup_rollball_proto(struct sfp *sfp, unsigned int secs)

static void sfp_fixup_rollball(struct sfp *sfp)

{

	sfp->mdio_protocol = MDIO_I2C_ROLLBALL;

	sfp->module_t_wait = msecs_to_jiffies(secs * 1000);



	/* RollBall modules may disallow access to PHY registers for up to 25

	 * seconds, and the reads return 0xffff before that. Increase the time

	 * between PHY probe retries from 50ms to 1s so that we will wait for

	 * the PHY for a sufficient amount of time.

	 */

	sfp->phy_t_retry = msecs_to_jiffies(1000);

}



static void sfp_fixup_fs_10gt(struct sfp *sfp)

{

	sfp_fixup_10gbaset_30m(sfp);



	// These SFPs need 4 seconds before the PHY can be accessed

	sfp_fixup_rollball_proto(sfp, 4);

	sfp_fixup_rollball(sfp);

}



static void sfp_fixup_halny_gsfp(struct sfp *sfp)
@@ -395,12 +399,6 @@ static void sfp_fixup_halny_gsfp(struct sfp *sfp) 
	sfp->state_hw_mask &= ~(SFP_F_TX_FAULT | SFP_F_LOS);

}



static void sfp_fixup_rollball(struct sfp *sfp)

{

	// Rollball SFPs need 25 seconds before the PHY can be accessed

	sfp_fixup_rollball_proto(sfp, 25);

}



static void sfp_fixup_rollball_cc(struct sfp *sfp)

{

	sfp_fixup_rollball(sfp);
@@ -2331,7 +2329,7 @@ static int sfp_sm_mod_probe(struct sfp *sfp, bool report) 
		mask |= SFP_F_RS1;



	sfp->module_t_start_up = T_START_UP;

	sfp->module_t_wait = T_WAIT;

	sfp->phy_t_retry = T_PHY_RETRY;



	sfp->state_ignore_mask = 0;
@@ -2568,10 +2566,9 @@ static void sfp_sm_main(struct sfp *sfp, unsigned int event) 


		/* We need to check the TX_FAULT state, which is not defined

		 * while TX_DISABLE is asserted. The earliest we want to do

		 * anything (such as probe for a PHY) is 50ms (or more on

		 * specific modules).

		 * anything (such as probe for a PHY) is 50ms.

		 */

		sfp_sm_next(sfp, SFP_S_WAIT, sfp->module_t_wait);

		sfp_sm_next(sfp, SFP_S_WAIT, T_WAIT);

		break;



	case SFP_S_WAIT:
@@ -2585,8 +2582,8 @@ static void sfp_sm_main(struct sfp *sfp, unsigned int event) 
			 * deasserting.

			 */

			timeout = sfp->module_t_start_up;

			if (timeout > sfp->module_t_wait)

				timeout -= sfp->module_t_wait;

			if (timeout > T_WAIT)

				timeout -= T_WAIT;

			else

				timeout = 1;
@@ -2629,7 +2626,11 @@ static void sfp_sm_main(struct sfp *sfp, unsigned int event) 
		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);

				sfp_sm_next(sfp, SFP_S_INIT_PHY,

					    sfp->phy_t_retry);

				dev_dbg(sfp->dev,

					"no PHY detected, %u tries left\n",

					sfp->sm_phy_retries);

				break;

			} else {

				dev_info(sfp->dev, "no PHY detected\n");