Patch "usb: chipidea: vbus event may exist before starting gadget" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

usb: chipidea: vbus event may exist before starting gadget

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
usb-chipidea-vbus-event-may-exist-before-starting-gadget.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Peter Chen <[email protected]>
Date: Wed, 19 Oct 2016 15:32:58 +0800
Subject: usb: chipidea: vbus event may exist before starting gadget

From: Peter Chen <[email protected]>

[ Upstream commit c3b674a04b8ab62a1d35e86714d466af0a0ecc18 ]

At some situations, the vbus may already be there before starting gadget. So we need to check vbus event after switching to gadget in order to handle missing vbus event. The typical use cases are plugging vbus cable before driver load or the vbus has already been there after stopping host but before starting gadget.

---
 drivers/usb/chipidea/otg.c |   17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

@@ -134,9 +134,9 @@ void ci_handle_vbus_change(struct ci_hdr
 	if (!ci->is_otg)
 		return;
 
-	if (hw_read_otgsc(ci, OTGSC_BSV))
+	if (hw_read_otgsc(ci, OTGSC_BSV) && !ci->vbus_active)
 		usb_gadget_vbus_connect(&ci->gadget);
-	else
+	else if (!hw_read_otgsc(ci, OTGSC_BSV) && ci->vbus_active)
 		usb_gadget_vbus_disconnect(&ci->gadget);
 }
 

@@ -175,14 +175,21 @@ static void ci_handle_id_switch(struct c
 
 		ci_role_stop(ci);
 
-		if (role == CI_ROLE_GADGET)
+		if (role == CI_ROLE_GADGET &&
+				IS_ERR(ci->platdata->vbus_extcon.edev))
 			/*
-			 * wait vbus lower than OTGSC_BSV before connecting
-			 * to host
+			 * Wait vbus lower than OTGSC_BSV before connecting
+			 * to host. If connecting status is from an external
+			 * connector instead of register, we don't need to
+			 * care vbus on the board, since it will not affect
+			 * external connector status.
 			 */
 			hw_wait_vbus_lower_bsv(ci);
 
 		ci_role_start(ci, role);
+		/* vbus change may have already occurred */
+		if (role == CI_ROLE_GADGET)
+			ci_handle_vbus_change(ci);
 	}
 }
 /**

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/usb-chipidea-vbus-event-may-exist-before-starting-gadget.patch