This is a note to let you know that I've just added the patch titled usb: common: otg-fsm: only signal connect after switching to peripheral to the 3.19-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-common-otg-fsm-only-signal-connect-after-switching-to-peripheral.patch and it can be found in the queue-3.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From a886bd92267c9e3d5c912860c6fb5a68479a7643 Mon Sep 17 00:00:00 2001 From: Peter Chen <peter.chen@xxxxxxxxxxxxx> Date: Thu, 12 Mar 2015 09:47:53 +0800 Subject: usb: common: otg-fsm: only signal connect after switching to peripheral From: Peter Chen <peter.chen@xxxxxxxxxxxxx> commit a886bd92267c9e3d5c912860c6fb5a68479a7643 upstream. 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 Fixes: the issue existed when the otg fsm code was added. Signed-off-by: Peter Chen <peter.chen@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/common/usb-otg-fsm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- 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 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 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: Patches currently in stable-queue which might be from peter.chen@xxxxxxxxxxxxx are queue-3.19/usb-common-otg-fsm-only-signal-connect-after-switching-to-peripheral.patch queue-3.19/usb-chipidea-otg-add-a_alt_hnp_support-response-for-b-device.patch -- 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