Thread (65 messages) 65 messages, 5 authors, 2016-08-26

[PATCH v2 09/22] usb: chipidea: Kick OTG state machine for AVVIS with vbus extcon

From: Peter Chen <hidden>
Date: 2016-07-11 02:33:24
Also in: linux-arm-msm, lkml

On Thu, Jul 07, 2016 at 03:21:00PM -0700, Stephen Boyd wrote:
quoted hunk ↗ jump to hunk
Force the OTG state machine to go forward when we're using an
extcon for vbus detection. In this case, the controller may never
raise an interrupt for AVVIS, so we need to simulate the event by
toggling the appropriate OTG fsm bits and kicking the state
machine again.

Cc: Peter Chen <redacted>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stephen Boyd <redacted>
---

I think this was rejected last time around but I've kept it in the
series to continue discussion on how we're supposed to be emulating
vbus an id pin interrupts and the otgsc register.

 drivers/usb/chipidea/otg_fsm.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
diff --git a/drivers/usb/chipidea/otg_fsm.c b/drivers/usb/chipidea/otg_fsm.c
index de8e22ec3902..aab076fc4d82 100644
--- a/drivers/usb/chipidea/otg_fsm.c
+++ b/drivers/usb/chipidea/otg_fsm.c
@@ -475,6 +475,14 @@ static void ci_otg_drv_vbus(struct otg_fsm *fsm, int on)
 				return;
 			}
 		}
+		/*
+		 * Force state machine forward if we use extcon
+		 * to detect vbus state (i.e. simulate AVVIS event)
+		 */
+		if (!IS_ERR(ci->platdata->vbus_extcon.edev)) {
+			fsm->a_vbus_vld = 1;
+			ci_otg_queue_work(ci);
+		}
 		/* Disable data pulse irq */
 		hw_write_otgsc(ci, OTGSC_DPIE, 0);
 
@@ -486,6 +494,15 @@ static void ci_otg_drv_vbus(struct otg_fsm *fsm, int on)
 
 		fsm->a_bus_drop = 1;
 		fsm->a_bus_req = 0;
+		/*
+		 * Force state machine forward if we use extcon
+		 * to detect vbus state (i.e. simulate AVVIS event)
+		 */
+		if (!IS_ERR(ci->platdata->vbus_extcon.edev)) {
+			fsm->a_vbus_vld = 0;
+			fsm->b_conn = 0;
+			ci_otg_queue_work(ci);
+		}
 	}
 }
 
Well, if we don't have a_valid, we can't know a_vbus_err state at
A device side if vbus is error (eg, less than 4.4v), and B device
will NOT be disconnect if vbus is still larger than BSV.

Do you really need OTG FSM? If you can pass the OTG test described at
Documentation/usb/chipidea.txt, I can accept it, I find the OTG
compliance test does not test ~a_vbus_vld either, see
otgeh_compliance_plan_1_2, ch6.7.12.2 Paths not tested.

-- 

Best Regards,
Peter Chen
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