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Commit 172cec3a authored by Jack Pham's avatar Jack Pham
Browse files

usb: pd: Improve sink hard reset handling 



During hard reset in sink mode, move the wait for VBUS to
reconnect to the PE_SNK_TRANSITION_TO_DEFAULT state. Use
the hrtimer to wait up to the maximum expected time for
VBUS to come back, which is triggered by the CC notification
from psy_changed(). This simplifies PE_SNK_STARTUP to only be
invoked when VBUS is already present and eliminates the
PE_SNK_DISCOVERY state.

When a non-PD source is connected, as the engine attempts to
wait for source capabilities this will result in hard reset
getting attempted 3 times with the hrtimer reaching full
timeout each time (for a total of ~6s) before settling.

Change-Id: Iee74c206b28fea9b75df2d234609a7939bc3d93c
Signed-off-by: default avatarJack Pham <jackp@codeaurora.org>
parent 773f15cd

drivers/usb/pd/policy_engine.c

+26 −32
Original line number Diff line number Diff line
@@ -170,6 +170,9 @@ static void *usbpd_ipc_log; 
#define PS_SOURCE_OFF		750

#define VDM_BUSY_TIME		50



/* tPSHardReset + tSafe0V + tSrcRecover + tSrcTurnOn */

#define SNK_HARD_RESET_RECOVER_TIME	(35 + 650 + 1000 + 275)



#define PD_CAPS_COUNT		50



#define PD_MAX_MSG_ID		7
@@ -800,18 +803,6 @@ static void usbpd_set_state(struct usbpd *pd, enum usbpd_state next_state) 
		pd->in_pr_swap = false;

		pd->current_voltage = 5000000;



		if (!pd->vbus_present) {

			/* can get here during a hard reset and we lost vbus */

			pd->current_state = PE_SNK_DISCOVERY;

			hrtimer_start(&pd->timer, ms_to_ktime(2000),

					HRTIMER_MODE_REL);

			break;

		}



		/*

		 * If VBUS is already present go and skip ahead to

		 * PE_SNK_WAIT_FOR_CAPABILITIES.

		 */

		pd->current_state = PE_SNK_WAIT_FOR_CAPABILITIES;

		/* fall-through */
@@ -882,8 +873,10 @@ static void usbpd_set_state(struct usbpd *pd, enum usbpd_state next_state) 
				POWER_SUPPLY_PROP_VOLTAGE_MAX, &val);

		pd->current_voltage = pd->requested_voltage;



		/* recursive call; go back to beginning state */

		usbpd_set_state(pd, PE_SNK_STARTUP);

		/* max time for hard reset to toggle vbus off/on */

		hrtimer_start(&pd->timer,

				ms_to_ktime(SNK_HARD_RESET_RECOVER_TIME),

				HRTIMER_MODE_REL);

		break;



	default:
@@ -1465,21 +1458,6 @@ static void usbpd_sm(struct work_struct *w) 
		usbpd_set_state(pd, PE_SRC_TRANSITION_TO_DEFAULT);

		break;



	case PE_SNK_DISCOVERY:

		if (!pd->vbus_present) {

			/* Hard reset and VBUS didn't come back? */

			power_supply_get_property(pd->usb_psy,

					POWER_SUPPLY_PROP_TYPE, &val);

			if (val.intval == POWER_SUPPLY_TYPEC_NONE) {

				pd->typec_mode = POWER_SUPPLY_TYPEC_NONE;

				queue_work(pd->wq, &pd->sm_work);

			}

			break;

		}



		usbpd_set_state(pd, PE_SNK_WAIT_FOR_CAPABILITIES);

		break;



	case PE_SNK_WAIT_FOR_CAPABILITIES:

		if (data_recvd == MSG_SOURCE_CAPABILITIES) {

			val.intval = 1;
@@ -1611,6 +1589,20 @@ static void usbpd_sm(struct work_struct *w) 
		}

		break;



	case PE_SNK_TRANSITION_TO_DEFAULT:

		if (pd->vbus_present) {

			usbpd_set_state(pd, PE_SNK_STARTUP);

		} else {

			/* Hard reset and VBUS didn't come back? */

			power_supply_get_property(pd->usb_psy,

					POWER_SUPPLY_PROP_TYPEC_MODE, &val);

			if (val.intval == POWER_SUPPLY_TYPEC_NONE) {

				pd->typec_mode = POWER_SUPPLY_TYPEC_NONE;

				queue_work(pd->wq, &pd->sm_work);

			}

		}

		break;



	case PE_SRC_SOFT_RESET:

	case PE_SNK_SOFT_RESET:

		/* Reset protocol layer */
@@ -1846,11 +1838,12 @@ static int psy_changed(struct notifier_block *nb, unsigned long evt, void *ptr) 
	 * until the HW bug is fixed: in which disconnection won't be reported

	 * on VBUS loss alone unless pullup is also removed from CC.

	 */

	if ((pd->hard_reset || pd->in_pr_swap) &&

	if ((pd->current_state == PE_SNK_TRANSITION_TO_DEFAULT ||

				pd->in_pr_swap) &&

			typec_mode == POWER_SUPPLY_TYPEC_NONE &&

			pd->psy_type != POWER_SUPPLY_TYPE_USB) {

		usbpd_dbg(&pd->dev, "Ignoring disconnect due to %s\n",

				pd->hard_reset ? "hard reset" : "PR swap");

				pd->in_pr_swap ? "PR swap" : "hard reset");

		return 0;

	}
@@ -1885,7 +1878,8 @@ static int psy_changed(struct notifier_block *nb, unsigned long evt, void *ptr) 
	case POWER_SUPPLY_TYPEC_SOURCE_HIGH:

		usbpd_info(&pd->dev, "Type-C Source (%s) connected\n",

				src_current(typec_mode));

		if (pd->current_pr != PR_SINK) {

		if (pd->current_pr != PR_SINK ||

			pd->current_state == PE_SNK_TRANSITION_TO_DEFAULT) {

			pd->current_pr = PR_SINK;

			queue_work(pd->wq, &pd->sm_work);

		}