Subject: Re: [PATCH v6 07/12] usb: otg: add OTG/dual-role core
To: Peter Chen <hzpeterchen@gmail.com>
References: <1459865117-7032-1-git-send-email-rogerq@ti.com>
 <1459865117-7032-8-git-send-email-rogerq@ti.com>
 <20160415092534.GA21274@shlinux2.ap.freescale.net>
CC: <stern@rowland.harvard.edu>, <balbi@kernel.org>,
        <gregkh@linuxfoundation.org>, <peter.chen@freescale.com>,
        <dan.j.williams@intel.com>, <jun.li@freescale.com>,
        <mathias.nyman@linux.intel.com>, <tony@atomide.com>,
        <Joao.Pinto@synopsys.com>, <abrestic@chromium.org>,
        <r.baldyga@samsung.com>, <linux-usb@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <linux-omap@vger.kernel.org>
From: Roger Quadros <rogerq@ti.com>
Message-ID: <5710C9DE.2050106@ti.com>
Date: Fri, 15 Apr 2016 14:00:46 +0300
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On 15/04/16 12:25, Peter Chen wrote:
> On Tue, Apr 05, 2016 at 05:05:12PM +0300, Roger Quadros wrote:
>> + * usb_otg_register() - Register the OTG/dual-role device to OTG core
>> + * @dev: OTG/dual-role controller device.
>> + * @config: OTG configuration.
>> + *
>> + * Registers the OTG/dual-role controller device with the USB OTG core.
>> + *
>> + * Return: struct usb_otg * if success, ERR_PTR() if error.
>> + */
>> +struct usb_otg *usb_otg_register(struct device *dev,
>> +				 struct usb_otg_config *config)
>> +{
>> +	struct usb_otg *otg;
>> +	struct otg_wait_data *wait;
>> +	int ret = 0;
>> +
>> +	if (!dev || !config || !config->fsm_ops)
>> +		return ERR_PTR(-EINVAL);
>> +
>> +	/* already in list? */
>> +	mutex_lock(&otg_list_mutex);
>> +	if (usb_otg_get_data(dev)) {
>> +		dev_err(dev, "otg: %s: device already in otg list\n",
>> +			__func__);
>> +		ret = -EINVAL;
>> +		goto unlock;
>> +	}
>> +
>> +	/* allocate and add to list */
>> +	otg = kzalloc(sizeof(*otg), GFP_KERNEL);
>> +	if (!otg) {
>> +		ret = -ENOMEM;
>> +		goto unlock;
>> +	}
>> +
>> +	otg->dev = dev;
>> +	otg->caps = config->otg_caps;
>> +
>> +	if ((otg->caps->hnp_support || otg->caps->srp_support ||
>> +	     otg->caps->adp_support) && !config->otg_work)
>> +		dev_info(dev, "otg: limiting to dual-role\n");
> 
> What does above mean? Customized otg_work item may be dual-role,
> may be full otg.

I'm checking for !config->otg_work so we're sure of using the
default dual-role only work function.

> 
>> +
>> +	if (config->otg_work)	/* custom otg_work ? */
>> +		INIT_WORK(&otg->work, config->otg_work);
>> +	else
>> +		INIT_WORK(&otg->work, usb_otg_work);
>> +
>> +	otg->wq = create_singlethread_workqueue("usb_otg");
>> +	if (!otg->wq) {
>> +		dev_err(dev, "otg: %s: can't create workqueue\n",
>> +			__func__);
>> +		ret = -ENOMEM;
>> +		goto err_wq;
>> +	}
> 
> I found a bug that caused by non-freezable workqueue, change it
> as freezable please.
> 
> https://marc.ttias.be/linux-stable/2016-03/msg00723.php

OK.

> 
> I will review the whole set from next week.

Thanks.

--
cheers,
-roger