Commit 80b6265c authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'net-phy-improve-and-simplify-phylib-state-machine' 



Heiner Kallweit says:

====================
net: phy: improve and simplify phylib state machine

This patch series is based on two axioms:

- During autoneg a PHY always reports the link being down

- Info in clause 22/45 registers doesn't allow to differentiate between
  these two states:
  1. Link is physically down
  2. A link partner is connected and PHY is autonegotiating
  In both cases "link up" and "aneg finished" bits aren't set.
  One consequence is that having separate states PHY_NOLINK and PHY_AN
  isn't needed.

By using these two axioms the state machine can be significantly
simplified.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 5867b330 c8e977ba

drivers/net/phy/phy.c

+45 −127
Original line number Original line Diff line number Diff line
@@ -50,7 +50,6 @@ static const char *phy_state_to_str(enum phy_state st) 
	PHY_STATE_STR(READY)

	PHY_STATE_STR(READY)

	PHY_STATE_STR(PENDING)

	PHY_STATE_STR(PENDING)

	PHY_STATE_STR(UP)

	PHY_STATE_STR(UP)

	PHY_STATE_STR(AN)

	PHY_STATE_STR(RUNNING)

	PHY_STATE_STR(RUNNING)

	PHY_STATE_STR(NOLINK)

	PHY_STATE_STR(NOLINK)

	PHY_STATE_STR(FORCING)

	PHY_STATE_STR(FORCING)
@@ -62,6 +61,17 @@ static const char *phy_state_to_str(enum phy_state st) 
	return NULL;

	return NULL;

}

}





static void phy_link_up(struct phy_device *phydev)

{

	phydev->phy_link_change(phydev, true, true);

	phy_led_trigger_change_speed(phydev);

}



static void phy_link_down(struct phy_device *phydev, bool do_carrier)

{

	phydev->phy_link_change(phydev, false, do_carrier);

	phy_led_trigger_change_speed(phydev);

}





/**

/**

 * phy_print_status - Convenience function to print out the current phy status

 * phy_print_status - Convenience function to print out the current phy status
@@ -493,6 +503,34 @@ static int phy_config_aneg(struct phy_device *phydev) 
	return genphy_config_aneg(phydev);

	return genphy_config_aneg(phydev);

}

}





/**

 * phy_check_link_status - check link status and set state accordingly

 * @phydev: the phy_device struct

 *

 * Description: Check for link and whether autoneg was triggered / is running

 * and set state accordingly

 */

static int phy_check_link_status(struct phy_device *phydev)

{

	int err;



	WARN_ON(!mutex_is_locked(&phydev->lock));



	err = phy_read_status(phydev);

	if (err)

		return err;



	if (phydev->link && phydev->state != PHY_RUNNING) {

		phydev->state = PHY_RUNNING;

		phy_link_up(phydev);

	} else if (!phydev->link && phydev->state != PHY_NOLINK) {

		phydev->state = PHY_NOLINK;

		phy_link_down(phydev, true);

	}



	return 0;

}



/**

/**

 * phy_start_aneg - start auto-negotiation for this PHY device

 * phy_start_aneg - start auto-negotiation for this PHY device

 * @phydev: the phy_device struct

 * @phydev: the phy_device struct
@@ -504,7 +542,6 @@ static int phy_config_aneg(struct phy_device *phydev) 
 */

 */

int phy_start_aneg(struct phy_device *phydev)

int phy_start_aneg(struct phy_device *phydev)

{

{

	bool trigger = 0;

	int err;

	int err;





	if (!phydev->drv)

	if (!phydev->drv)
@@ -524,32 +561,16 @@ int phy_start_aneg(struct phy_device *phydev) 




	if (phydev->state != PHY_HALTED) {

	if (phydev->state != PHY_HALTED) {

		if (AUTONEG_ENABLE == phydev->autoneg) {

		if (AUTONEG_ENABLE == phydev->autoneg) {

			phydev->state = PHY_AN;

			err = phy_check_link_status(phydev);

			phydev->link_timeout = PHY_AN_TIMEOUT;

		} else {

		} else {

			phydev->state = PHY_FORCING;

			phydev->state = PHY_FORCING;

			phydev->link_timeout = PHY_FORCE_TIMEOUT;

			phydev->link_timeout = PHY_FORCE_TIMEOUT;

		}

		}

	}

	}





	/* Re-schedule a PHY state machine to check PHY status because

	 * negotiation may already be done and aneg interrupt may not be

	 * generated.

	 */

	if (!phy_polling_mode(phydev) && phydev->state == PHY_AN) {

		err = phy_aneg_done(phydev);

		if (err > 0) {

			trigger = true;

			err = 0;

		}

	}



out_unlock:

out_unlock:

	mutex_unlock(&phydev->lock);

	mutex_unlock(&phydev->lock);





	if (trigger)

		phy_trigger_machine(phydev);



	return err;

	return err;

}

}

EXPORT_SYMBOL(phy_start_aneg);

EXPORT_SYMBOL(phy_start_aneg);
@@ -893,18 +914,6 @@ void phy_start(struct phy_device *phydev) 
}

}

EXPORT_SYMBOL(phy_start);

EXPORT_SYMBOL(phy_start);





static void phy_link_up(struct phy_device *phydev)

{

	phydev->phy_link_change(phydev, true, true);

	phy_led_trigger_change_speed(phydev);

}



static void phy_link_down(struct phy_device *phydev, bool do_carrier)

{

	phydev->phy_link_change(phydev, false, do_carrier);

	phy_led_trigger_change_speed(phydev);

}



/**

/**

 * phy_state_machine - Handle the state machine

 * phy_state_machine - Handle the state machine

 * @work: work_struct that describes the work to be done

 * @work: work_struct that describes the work to be done
@@ -934,56 +943,15 @@ void phy_state_machine(struct work_struct *work) 
	case PHY_UP:

	case PHY_UP:

		needs_aneg = true;

		needs_aneg = true;





		phydev->link_timeout = PHY_AN_TIMEOUT;



		break;

	case PHY_AN:

		err = phy_read_status(phydev);

		if (err < 0)

			break;



		/* If the link is down, give up on negotiation for now */

		if (!phydev->link) {

			phydev->state = PHY_NOLINK;

			phy_link_down(phydev, true);

			break;

		}



		/* Check if negotiation is done.  Break if there's an error */

		err = phy_aneg_done(phydev);

		if (err < 0)

			break;



		/* If AN is done, we're running */

		if (err > 0) {

			phydev->state = PHY_RUNNING;

			phy_link_up(phydev);

		} else if (0 == phydev->link_timeout--)

			needs_aneg = true;

		break;

		break;

	case PHY_NOLINK:

	case PHY_NOLINK:

	case PHY_RUNNING:

		if (!phy_polling_mode(phydev))

		if (!phy_polling_mode(phydev))

			break;

			break;



		/* fall through */

		err = phy_read_status(phydev);

	case PHY_CHANGELINK:

		if (err)

	case PHY_RESUMING:

			break;

		err = phy_check_link_status(phydev);



		if (phydev->link) {

			if (AUTONEG_ENABLE == phydev->autoneg) {

				err = phy_aneg_done(phydev);

				if (err < 0)

					break;



				if (!err) {

					phydev->state = PHY_AN;

					phydev->link_timeout = PHY_AN_TIMEOUT;

					break;

				}

			}

			phydev->state = PHY_RUNNING;

			phy_link_up(phydev);

		}

		break;

		break;

	case PHY_FORCING:

	case PHY_FORCING:

		err = genphy_update_link(phydev);

		err = genphy_update_link(phydev);
@@ -999,32 +967,6 @@ void phy_state_machine(struct work_struct *work) 
			phy_link_down(phydev, false);

			phy_link_down(phydev, false);

		}

		}

		break;

		break;

	case PHY_RUNNING:

		if (!phy_polling_mode(phydev))

			break;



		err = phy_read_status(phydev);

		if (err)

			break;



		if (!phydev->link) {

			phydev->state = PHY_NOLINK;

			phy_link_down(phydev, true);

		}

		break;

	case PHY_CHANGELINK:

		err = phy_read_status(phydev);

		if (err)

			break;



		if (phydev->link) {

			phydev->state = PHY_RUNNING;

			phy_link_up(phydev);

		} else {

			phydev->state = PHY_NOLINK;

			phy_link_down(phydev, true);

		}

		break;

	case PHY_HALTED:

	case PHY_HALTED:

		if (phydev->link) {

		if (phydev->link) {

			phydev->link = 0;

			phydev->link = 0;
@@ -1032,30 +974,6 @@ void phy_state_machine(struct work_struct *work) 
			do_suspend = true;

			do_suspend = true;

		}

		}

		break;

		break;

	case PHY_RESUMING:

		if (AUTONEG_ENABLE == phydev->autoneg) {

			err = phy_aneg_done(phydev);

			if (err < 0) {

				break;

			} else if (!err) {

				phydev->state = PHY_AN;

				phydev->link_timeout = PHY_AN_TIMEOUT;

				break;

			}

		}



		err = phy_read_status(phydev);

		if (err)

			break;



		if (phydev->link) {

			phydev->state = PHY_RUNNING;

			phy_link_up(phydev);

		} else	{

			phydev->state = PHY_NOLINK;

			phy_link_down(phydev, false);

		}

		break;

	}

	}





	mutex_unlock(&phydev->lock);

	mutex_unlock(&phydev->lock);

include/linux/phy.h

+1 −18
Original line number Original line Diff line number Diff line
@@ -178,7 +178,6 @@ static inline const char *phy_modes(phy_interface_t interface) 
#define PHY_INIT_TIMEOUT	100000

#define PHY_INIT_TIMEOUT	100000

#define PHY_STATE_TIME		1

#define PHY_STATE_TIME		1

#define PHY_FORCE_TIMEOUT	10

#define PHY_FORCE_TIMEOUT	10

#define PHY_AN_TIMEOUT		10





#define PHY_MAX_ADDR	32

#define PHY_MAX_ADDR	32
@@ -297,24 +296,10 @@ struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr); 
 *

 *

 * UP: The PHY and attached device are ready to do work.

 * UP: The PHY and attached device are ready to do work.

 * Interrupts should be started here.

 * Interrupts should be started here.

 * - timer moves to AN

 * - timer moves to NOLINK or RUNNING

 *

 * AN: The PHY is currently negotiating the link state.  Link is

 * therefore down for now.  phy_timer will set this state when it

 * detects the state is UP.  config_aneg will set this state

 * whenever called with phydev->autoneg set to AUTONEG_ENABLE.

 * - If autonegotiation finishes, but there's no link, it sets

 *   the state to NOLINK.

 * - If aneg finishes with link, it sets the state to RUNNING,

 *   and calls adjust_link

 * - If autonegotiation did not finish after an arbitrary amount

 *   of time, autonegotiation should be tried again if the PHY

 *   supports "magic" autonegotiation (back to AN)

 * - If it didn't finish, and no magic_aneg, move to FORCING.

 *

 *

 * NOLINK: PHY is up, but not currently plugged in.

 * NOLINK: PHY is up, but not currently plugged in.

 * - If the timer notes that the link comes back, we move to RUNNING

 * - If the timer notes that the link comes back, we move to RUNNING

 * - config_aneg moves to AN

 * - phy_stop moves to HALTED

 * - phy_stop moves to HALTED

 *

 *

 * FORCING: PHY is being configured with forced settings

 * FORCING: PHY is being configured with forced settings
@@ -329,7 +314,6 @@ struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr); 
 *   link state is polled every other cycle of this state machine,

 *   link state is polled every other cycle of this state machine,

 *   which makes it every other second)

 *   which makes it every other second)

 * - irq will set CHANGELINK

 * - irq will set CHANGELINK

 * - config_aneg will set AN

 * - phy_stop moves to HALTED

 * - phy_stop moves to HALTED

 *

 *

 * CHANGELINK: PHY experienced a change in link state

 * CHANGELINK: PHY experienced a change in link state
@@ -353,7 +337,6 @@ enum phy_state { 
	PHY_READY,

	PHY_READY,

	PHY_PENDING,

	PHY_PENDING,

	PHY_UP,

	PHY_UP,

	PHY_AN,

	PHY_RUNNING,

	PHY_RUNNING,

	PHY_NOLINK,

	PHY_NOLINK,

	PHY_FORCING,

	PHY_FORCING,

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