From: Peter Chen <hzpeterchen@gmail.com>
To: Roger Quadros <rogerq@ti.com>
Cc: peter.chen@freescale.com, balbi@kernel.org, tony@atomide.com,
gregkh@linuxfoundation.org, dan.j.williams@intel.com,
mathias.nyman@linux.intel.com, Joao.Pinto@synopsys.com,
sergei.shtylyov@cogentembedded.com, jun.li@freescale.com,
grygorii.strashko@ti.com, yoshihiro.shimoda.uh@renesas.com,
robh@kernel.org, nsekhar@ti.com, b-liu@ti.com,
linux-usb@vger.kernel.org, linux-omap@vger.kernel.org,
linux-kernel@vger.kernel.org, devicetree@vger.kernel.org
Subject: Re: [PATCH v9 08/14] usb: otg: add OTG/dual-role core
Date: Sun, 12 Jun 2016 18:56:27 +0800 [thread overview]
Message-ID: <20160612105627.GA32615@shlinux2> (raw)
In-Reply-To: <20160612062617.GC22054@shlinux2>
On Sun, Jun 12, 2016 at 02:26:17PM +0800, Peter Chen wrote:
> On Thu, Jun 09, 2016 at 10:24:44AM +0300, Roger Quadros wrote:
> > On 08/06/16 15:42, Peter Chen wrote:
> > > On Wed, Jun 08, 2016 at 01:12:10PM +0300, Roger Quadros wrote:
> > >> Hi,
> > >>
> > >> On 08/06/16 12:53, Peter Chen wrote:
> > >>> On Wed, Jun 08, 2016 at 12:03:40PM +0300, Roger Quadros wrote:
> > >>>> +int usb_otg_unregister(struct device *dev)
> > >>>> +{
> > >>>> + struct usb_otg *otg;
> > >>>> +
> > >>>> + mutex_lock(&otg_list_mutex);
> > >>>> + otg = usb_otg_get_data(dev);
> > >>>> + if (!otg) {
> > >>>> + dev_err(dev, "otg: %s: device not in otg list\n",
> > >>>> + __func__);
> > >>>> + mutex_unlock(&otg_list_mutex);
> > >>>> + return -EINVAL;
> > >>>> + }
> > >>>> +
> > >>>> + /* prevent unregister till both host & gadget have unregistered */
> > >>>> + if (otg->host || otg->gadget) {
> > >>>> + dev_err(dev, "otg: %s: host/gadget still registered\n",
> > >>>> + __func__);
> > >>>
> > >>> You need to call mutex_unlock here
> > >>
> > >> Indeed. good catch.
> > >>>
> > >>>> +
> > >>>> +int usb_otg_gadget_ready(struct usb_gadget *gadget, bool ready)
> > >>>> +{
> > >>>
> > >>> What this API is for? Why need it in this version?
> > >>
> > >> we moved gadget to otg registration from udc_bind_to_driver() to usb_add_gadget_udc_release().
> > >> This means there is a window when gadget function driver (e.g. g_zero) is not loaded.
> > >> We don't want to start the gadget controller in that window.
> > >>
> > >> usb_otg_gadget_ready() is used by gadget core to notify the otg core when the function driver
> > >> is ready or not-ready.
> > >>
> > >
> > > Why you need to move this from gadget's probe to udc's probe? Currently,
> > > the sequence of gadget and udc's probe is random, but udc_bind_to_driver
> > > is called when udc is ready.
> > >
> > Because we need to support -EPROBE_DEFER at udc probe.
> > At udc_bind_to_driver there is no scope for -EPROBE_DEFER.
> >
>
> Why udc_bind_to_driver can't return -EPROBE_DEFER if register to OTG is
> failed?
>
> > Another issue is that we need to register with otg and have otg->caps available
> > before driver->bind() is called in udc_bind_to_driver(). Else gadget function
> > will not have the correct OTG descriptor.
> >
>
> You can do register before calling driver->bind.
>
Please skip my comments, I understand your changes now.
--
Best Regards,
Peter Chen
next prev parent reply other threads:[~2016-06-12 10:56 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-08 9:03 [PATCH v9 00/14] USB OTG/dual-role framework Roger Quadros
2016-06-08 9:03 ` [PATCH v9 01/14] usb: hcd: Initialize hcd->flags to 0 Roger Quadros
2016-06-08 9:03 ` [PATCH v9 02/14] usb: otg-fsm: Prevent build warning "VDBG" redefined Roger Quadros
2016-06-08 9:03 ` [PATCH v9 03/14] usb: hcd.h: Add OTG to HCD interface Roger Quadros
[not found] ` <1465376626-30122-4-git-send-email-rogerq-l0cyMroinI0@public.gmane.org>
2016-06-08 11:39 ` Sergei Shtylyov
2016-06-08 12:04 ` Roger Quadros
[not found] ` <575809E9.7010409-l0cyMroinI0@public.gmane.org>
2016-06-08 12:10 ` Sergei Shtylyov
[not found] ` <f5f068ae-c46a-5bad-45e1-f0f9cb5f8592-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8@public.gmane.org>
2016-06-09 7:31 ` Roger Quadros
2016-06-09 10:16 ` Sergei Shtylyov
[not found] ` <5201761f-4efa-f941-b05f-e4a2b91c75c0-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8@public.gmane.org>
2016-06-09 14:11 ` Alan Stern
2016-06-10 7:01 ` Roger Quadros
2016-06-09 7:51 ` [PATCH v10 " Roger Quadros
2016-06-08 9:03 ` [PATCH v9 04/14] usb: otg-fsm: use usb_otg wherever possible Roger Quadros
2016-06-08 9:03 ` [PATCH v9 05/14] usb: otg-fsm: move host controller operations into usb_otg->hcd_ops Roger Quadros
2016-06-08 9:03 ` [PATCH v9 06/14] usb: gadget.h: Add OTG to gadget interface Roger Quadros
2016-06-08 9:03 ` [PATCH v9 07/14] usb: otg: get rid of CONFIG_USB_OTG_FSM in favour of CONFIG_USB_OTG Roger Quadros
2016-06-08 9:03 ` [PATCH v9 08/14] usb: otg: add OTG/dual-role core Roger Quadros
2016-06-08 9:53 ` Peter Chen
2016-06-08 10:12 ` Roger Quadros
[not found] ` <5757EF7A.20604-l0cyMroinI0@public.gmane.org>
2016-06-08 12:42 ` Peter Chen
2016-06-09 7:24 ` Roger Quadros
[not found] ` <575919BC.8080003-l0cyMroinI0@public.gmane.org>
2016-06-12 6:26 ` Peter Chen
2016-06-12 10:56 ` Peter Chen [this message]
2016-06-09 7:53 ` [PATCH v10 " Roger Quadros
2016-06-09 12:34 ` Sergei Shtylyov
2016-06-10 7:04 ` Roger Quadros
2016-06-10 10:19 ` Roger Quadros
[not found] ` <575A9430.6070508-l0cyMroinI0@public.gmane.org>
2016-06-10 10:44 ` Sergei Shtylyov
2016-06-10 10:54 ` Roger Quadros
[not found] ` <575A9C7C.7020902-l0cyMroinI0@public.gmane.org>
2016-06-10 11:02 ` Felipe Balbi
2016-06-08 9:03 ` [PATCH v9 09/14] usb: of: add an API to get OTG device from USB controller node Roger Quadros
2016-06-08 9:03 ` [PATCH v9 10/14] usb: otg: add hcd companion support Roger Quadros
2016-06-08 9:03 ` [PATCH v9 11/14] usb: otg: use dev_dbg() instead of VDBG() Roger Quadros
[not found] ` <1465376626-30122-12-git-send-email-rogerq-l0cyMroinI0@public.gmane.org>
2016-06-08 15:10 ` Joe Perches
[not found] ` <1465398640.25087.50.camel-6d6DIl74uiNBDgjK7y7TUQ@public.gmane.org>
2016-06-09 7:25 ` Roger Quadros
2016-06-09 7:55 ` [PATCH v10 " Roger Quadros
[not found] ` <575920D9.7080905-l0cyMroinI0@public.gmane.org>
2016-06-09 15:43 ` Joe Perches
[not found] ` <1465487024.25087.72.camel-6d6DIl74uiNBDgjK7y7TUQ@public.gmane.org>
2016-06-10 7:05 ` Roger Quadros
2016-06-08 9:03 ` [PATCH v9 12/14] usb: hcd: Adapt to OTG core Roger Quadros
2016-06-08 11:42 ` Sergei Shtylyov
[not found] ` <22442eeb-e927-d7ac-52c6-3aebd2106837-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8@public.gmane.org>
2016-06-08 12:06 ` Roger Quadros
2016-06-08 12:11 ` Sergei Shtylyov
[not found] ` <21edbb67-8219-14ac-5c33-cabfd62d5fa1-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8@public.gmane.org>
2016-06-09 7:27 ` Roger Quadros
2016-06-08 9:03 ` [PATCH v9 13/14] usb: gadget: udc: adapt " Roger Quadros
[not found] ` <1465376626-30122-14-git-send-email-rogerq-l0cyMroinI0@public.gmane.org>
2016-06-09 10:49 ` Yoshihiro Shimoda
[not found] ` <SG2PR06MB09198DD132E005FFD4F4CAEED85F0-ESzmfEwOt/zNQ8RBPPB5A20DtJ1/0DrXvxpqHgZTriW3zl9H0oFU5g@public.gmane.org>
2016-06-10 7:06 ` Roger Quadros
2016-06-08 9:03 ` [PATCH v9 14/14] usb: host: xhci-plat: Add otg device to platform data Roger Quadros
[not found] ` <1465376626-30122-1-git-send-email-rogerq-l0cyMroinI0@public.gmane.org>
2016-06-09 5:27 ` [PATCH v9 00/14] USB OTG/dual-role framework Peter Chen
[not found] ` <CAL411-owotvsJVEnbFh5g8yK7YEPnnpBhYx9_tRf6NQET38L+A-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-06-09 7:30 ` Roger Quadros
2016-06-09 10:13 ` Yoshihiro Shimoda
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