Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755978AbcJTKKi (ORCPT ); Thu, 20 Oct 2016 06:10:38 -0400 Received: from mail-pf0-f195.google.com ([209.85.192.195]:32979 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751118AbcJTKKg (ORCPT ); Thu, 20 Oct 2016 06:10:36 -0400 Date: Thu, 20 Oct 2016 18:10:18 +0800 From: Peter Chen To: Stephen Boyd Cc: linux-usb@vger.kernel.org, Felipe Balbi , Arnd Bergmann , Neil Armstrong , linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, Bjorn Andersson , Peter Chen , Greg Kroah-Hartman , Andy Gross , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v5 11/23] usb: chipidea: Emulate OTGSC interrupt enable path Message-ID: <20161020101017.GA32001@b29397-desktop> References: <20161018015636.11701-1-stephen.boyd@linaro.org> <20161018015636.11701-12-stephen.boyd@linaro.org> <20161019011535.GC6294@b29397-desktop> <147684198705.24897.12451889548508263144@sboyd-linaro> <20161019080211.GA1968@b29397-desktop> <147694652997.28344.1048935134595924905@sboyd-linaro> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <147694652997.28344.1048935134595924905@sboyd-linaro> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5307 Lines: 128 On Wed, Oct 19, 2016 at 11:55:29PM -0700, Stephen Boyd wrote: > Quoting Peter Chen (2016-10-19 01:02:11) > > On Tue, Oct 18, 2016 at 06:53:07PM -0700, Stephen Boyd wrote: > > > If you're asking if I've made modifications to extcon-usb-gpio, then the > > > answer is no. The branch on linaro.org git server from the cover-letter > > > is the branch I've used to test this with. This patch is specifically to > > > fix issues with that design on the db410c board that has only one pin > > > for ID and vbus detection. It's the schematic that we've discussed in > > > another thread. > > > > > > extcon-usb-gpio sends two extcon events, EXTCON_USB_HOST (for the id > > > pin) and EXTCON_USB (for the vbus). So afaik it does support vbus > > > events. > > > > > > > Hmm, in fact, your ID event is the same with vbus event, you take > > external vbus event as ID event for extcon-usb-gpio handling. Yes, > > it can work due to it sends EXTCON_USB_HOST event first. > > > > Where you change the USB_SW_SEL_PM pin? > > Currently that is done with the mux driver I sent based on the extcon > event. We don't know if that's before or after the controller handles > the extcon event though, so the pin should probably be changed from the > chipidea driver instead to be more explicit. Why do you ask though? I was just curious how you handle it, now I am clear. From my point, the suitable way may be: mux driver + user app (echo role through debugfs). The extcon-usb-gpio is not necessary, since you have already known role at mux driver. The current kernel has no framework to handle dual-role switch at kernel space. > > At some situations, the vbus may already be there before starting > > gadget. So we need to check vbus event after switch 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. > > > > Signed-off-by: Peter Chen > > Yes this should work. Light testing doesn't show any problems so far. > > > --- > > drivers/usb/chipidea/core.c | 4 ---- > > drivers/usb/chipidea/otg.c | 10 ++++++---- > > drivers/usb/chipidea/udc.c | 2 ++ > > 3 files changed, 8 insertions(+), 8 deletions(-) > > > > diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c > > index b814d91..a7d2c68 100644 > > --- a/drivers/usb/chipidea/core.c > > +++ b/drivers/usb/chipidea/core.c > > @@ -992,10 +992,6 @@ static int ci_hdrc_probe(struct platform_device *pdev) > > } > > > > if (!ci_otg_is_fsm_mode(ci)) { > > - /* only update vbus status for peripheral */ > > - if (ci->role == CI_ROLE_GADGET) > > - ci_handle_vbus_change(ci); > > - > > ret = ci_role_start(ci, ci->role); > > if (ret) { > > dev_err(dev, "can't start %s role\n", > > diff --git a/drivers/usb/chipidea/otg.c b/drivers/usb/chipidea/otg.c > > index 695f3fe..99c0709 100644 > > --- a/drivers/usb/chipidea/otg.c > > +++ b/drivers/usb/chipidea/otg.c > > @@ -134,9 +134,9 @@ void ci_handle_vbus_change(struct ci_hdrc *ci) > > 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); > > } > > > > @@ -175,10 +175,12 @@ static void ci_handle_id_switch(struct ci_hdrc *ci) > > > > 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 > > + * to host. And if vbus's status is an external > > + * connector, it doesn't need to wait here. > > because OTGSC_BSV will toggle based on the extcon state and not when the > phy connects to the host? It would be good to explain why it's not > needed instead of just repeating what the code is doing. > Thanks, will change like below " 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); > > > > diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c > > index 001c2fa..184ffba 100644 > > --- a/drivers/usb/chipidea/udc.c > > +++ b/drivers/usb/chipidea/udc.c > > @@ -1963,6 +1963,8 @@ static int udc_id_switch_for_device(struct ci_hdrc *ci) > > /* Clear and enable BSV irq */ > > hw_write_otgsc(ci, OTGSC_BSVIS | OTGSC_BSVIE, > > OTGSC_BSVIS | OTGSC_BSVIE); > > + /* vbus change may has already been occurred */ > > "vbus change may have already occurred"? Yes, will change. -- Best Regards, Peter Chen