Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753600AbdDKPQh (ORCPT ); Tue, 11 Apr 2017 11:16:37 -0400 Received: from mail-pf0-f196.google.com ([209.85.192.196]:34521 "EHLO mail-pf0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751997AbdDKPQf (ORCPT ); Tue, 11 Apr 2017 11:16:35 -0400 Date: Tue, 11 Apr 2017 20:46:24 +0530 From: Niranjan Dighe To: Peter.Chen@freescale.com, gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] chipidea: Fix issue in reconnecing gadget without insmod/rmmod Message-ID: <20170411151624.GA4703@scoobydoo> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2716 Lines: 80 Currently usb_gadget_connect() is called only through gadget registration via composite_driver_probe(). As a result, after a disconnection, if the role transitions to host and back to gadget, the gadget is not recognized by the host anymore. This is a typical scenario with an iAP device in the following usecase - conn iAP dev -> send roleswitch command -> roleswitch ourself to gadget -> disconnect iAP device -> roleswitch back to host to enumerate the device again -> reconnect device -> resend the roleswitch command -> roleswitch ourself to gadget -> ISSUE. To workaround this, do the following - 1. Restart OTG FSM on SLi interrupt and on switching role to gadget so that device transitions to B_IDLE state from B_PERIPHERAL state. A transition from B_IDLE to B_PERIPHERAL is needed to enable interrups and restore the correct state of the chipidea controller so that communication with host is possible 2. usb_gadget_connect() after roleswitch to gadget so that gadget->ops->pullup() is called and D+ line is asserted. This causes host to "see" the device and enumeration can happen. Signed-off-by: Niranjan Dighe --- drivers/usb/chipidea/debug.c | 10 +++++++++- drivers/usb/chipidea/udc.c | 3 +++ 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/usb/chipidea/debug.c b/drivers/usb/chipidea/debug.c index a4f7db2..66c1485 100644 --- a/drivers/usb/chipidea/debug.c +++ b/drivers/usb/chipidea/debug.c @@ -16,7 +16,7 @@ #include "udc.h" #include "bits.h" #include "otg.h" - +extern void ci_hdrc_otg_fsm_restart(struct ci_hdrc *); /** * ci_device_show: prints information about device capabilities and status */ @@ -325,6 +325,14 @@ static ssize_t ci_role_write(struct file *file, const char __user *ubuf, ci_role_stop(ci); ret = ci_role_start(ci, role); enable_irq(ci->irq); + + /* REVISIT - Avoid repeated FSM restart*/ + + if (role == CI_ROLE_GADGET) { + ci_hdrc_otg_fsm_restart(ci); + usb_gadget_connect(&ci->gadget); + } + pm_runtime_put_sync(ci->dev); return ret ? ret : count; diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c index a0accd5..1e3b827 100644 --- a/drivers/usb/chipidea/udc.c +++ b/drivers/usb/chipidea/udc.c @@ -29,6 +29,8 @@ #include "otg.h" #include "otg_fsm.h" +extern void ci_hdrc_otg_fsm_restart(struct ci_hdrc *); + /* control endpoint description */ static const struct usb_endpoint_descriptor ctrl_endpt_out_desc = { @@ -1881,6 +1883,7 @@ static irqreturn_t udc_irq(struct ci_hdrc *ci) ci->driver->suspend(&ci->gadget); usb_gadget_set_state(&ci->gadget, USB_STATE_SUSPENDED); + ci_hdrc_otg_fsm_restart(ci); spin_lock(&ci->lock); } } -- 2.1.4