From: Roger Quadros <rogerq@ti.com>
To: Peter Chen <hzpeterchen@gmail.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: Thu, 9 Jun 2016 10:24:44 +0300 [thread overview]
Message-ID: <575919BC.8080003@ti.com> (raw)
In-Reply-To: <20160608124204.GB10029@shlinux2>
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.
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.
cheers,
-roger
next prev parent reply other threads:[~2016-06-09 7:25 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
2016-06-08 11:39 ` Sergei Shtylyov
2016-06-08 12:04 ` Roger Quadros
2016-06-08 12:10 ` Sergei Shtylyov
2016-06-09 7:31 ` Roger Quadros
2016-06-09 10:16 ` Sergei Shtylyov
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
2016-06-08 12:42 ` Peter Chen
2016-06-09 7:24 ` Roger Quadros [this message]
2016-06-12 6:26 ` Peter Chen
2016-06-12 10:56 ` Peter Chen
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
2016-06-10 10:44 ` Sergei Shtylyov
2016-06-10 10:54 ` Roger Quadros
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
2016-06-08 15:10 ` Joe Perches
2016-06-09 7:25 ` Roger Quadros
2016-06-09 7:55 ` [PATCH v10 " Roger Quadros
2016-06-09 15:43 ` Joe Perches
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
2016-06-08 12:06 ` Roger Quadros
2016-06-08 12:11 ` Sergei Shtylyov
2016-06-09 7:27 ` Roger Quadros
2016-06-08 9:03 ` [PATCH v9 13/14] usb: gadget: udc: adapt " Roger Quadros
2016-06-09 10:49 ` Yoshihiro Shimoda
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
2016-06-09 5:27 ` [PATCH v9 00/14] USB OTG/dual-role framework Peter Chen
2016-06-09 7:30 ` Roger Quadros
2016-06-09 10:13 ` Yoshihiro Shimoda
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