We should signal connect (pull up dp) after we have already at peripheral mode, otherwise, the dp may be toggled due to we reset controller or do disconnect during the initialization for peripheral, then, the host may be confused during the enumeration, eg, it finds the reset can't succeed, but the device is still there, see below error message. hub 1-0:1.0: USB hub found hub 1-0:1.0: 1 port detected hub 1-0:1.0: cannot reset port 1 (err = -32) hub 1-0:1.0: cannot reset port 1 (err = -32) hub 1-0:1.0: cannot reset port 1 (err = -32) hub 1-0:1.0: cannot reset port 1 (err = -32) hub 1-0:1.0: cannot reset port 1 (err = -32) hub 1-0:1.0: Cannot enable port 1. Maybe the USB cable is bad? hub 1-0:1.0: cannot reset port 1 (err = -32) hub 1-0:1.0: cannot reset port 1 (err = -32) hub 1-0:1.0: cannot reset port 1 (err = -32) hub 1-0:1.0: cannot reset port 1 (err = -32) hub 1-0:1.0: cannot reset port 1 (err = -32) hub 1-0:1.0: Cannot enable port 1. Maybe the USB cable is bad? hub 1-0:1.0: cannot reset port 1 (err = -32) hub 1-0:1.0: cannot reset port 1 (err = -32) hub 1-0:1.0: cannot reset port 1 (err = -32) hub 1-0:1.0: cannot reset port 1 (err = -32) hub 1-0:1.0: cannot reset port 1 (err = -32) hub 1-0:1.0: Cannot enable port 1. Maybe the USB cable is bad? hub 1-0:1.0: cannot reset port 1 (err = -32) hub 1-0:1.0: cannot reset port 1 (err = -32) hub 1-0:1.0: cannot reset port 1 (err = -32) hub 1-0:1.0: cannot reset port 1 (err = -32) hub 1-0:1.0: cannot reset port 1 (err = -32) hub 1-0:1.0: Cannot enable port 1. Maybe the USB cable is bad? hub 1-0:1.0: unable to enumerate USB device on port 1 Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Peter Chen <peter.chen@xxxxxxxxxxxxx> --- Changes for v2: - Add Cc tag for stable@xxxxxxxxxxxxxxx drivers/usb/common/usb-otg-fsm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/usb/common/usb-otg-fsm.c b/drivers/usb/common/usb-otg-fsm.c index c6b35b7..61d538a 100644 --- a/drivers/usb/common/usb-otg-fsm.c +++ b/drivers/usb/common/usb-otg-fsm.c @@ -150,9 +150,9 @@ static int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state) break; case OTG_STATE_B_PERIPHERAL: otg_chrg_vbus(fsm, 0); - otg_loc_conn(fsm, 1); otg_loc_sof(fsm, 0); otg_set_protocol(fsm, PROTO_GADGET); + otg_loc_conn(fsm, 1); break; case OTG_STATE_B_WAIT_ACON: otg_chrg_vbus(fsm, 0); @@ -213,10 +213,10 @@ static int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state) break; case OTG_STATE_A_PERIPHERAL: - otg_loc_conn(fsm, 1); otg_loc_sof(fsm, 0); otg_set_protocol(fsm, PROTO_GADGET); otg_drv_vbus(fsm, 1); + otg_loc_conn(fsm, 1); otg_add_timer(fsm, A_BIDL_ADIS); break; case OTG_STATE_A_WAIT_VFALL: -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html