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From: Yunzhi Li <lyz@rock-chips.com>
To: Paul Zimmerman <Paul.Zimmerman@synopsys.com>,
	"heiko@sntech.de" <heiko@sntech.de>,
	"dianders@chromium.org" <dianders@chromium.org>
Cc: "olof@lixom.net" <olof@lixom.net>,
	"huangtao@rock-chips.com" <huangtao@rock-chips.com>,
	"ulrich.prinz@googlemail.com" <ulrich.prinz@googlemail.com>,
	"zyw@rock-chips.com" <zyw@rock-chips.com>,
	"cf@rock-chips.com" <cf@rock-chips.com>,
	"linux-rockchip@lists.infradead.org" 
	<linux-rockchip@lists.infradead.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 3/5] usb: dwc2: Add generic PHY framework support for dwc2 usb controler platform driver.
Date: Mon, 08 Dec 2014 11:58:09 +0800	[thread overview]
Message-ID: <548521D1.2060509@rock-chips.com> (raw)
In-Reply-To: <A2CA0424C0A6F04399FB9E1CD98E0304844FFB50@US01WEMBX2.internal.synopsys.com>

Hi Paul:

Thank you for replying.

On 2014/12/6 3:04, Paul Zimmerman wrote:
>> From: Yunzhi Li [mailto:lyz@rock-chips.com]
>> Sent: Friday, December 05, 2014 4:52 AM
>>
>> Get PHY parameters from devicetree and power off usb PHY during
>> system suspend.
>>
>> Signed-off-by: Yunzhi Li <lyz@rock-chips.com>
>> ---
>>
>>   drivers/usb/dwc2/gadget.c   | 33 ++++++++++++---------------------
>>   drivers/usb/dwc2/platform.c | 34 ++++++++++++++++++++++++++++++++++
>>   2 files changed, 46 insertions(+), 21 deletions(-)
>>
>> diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
>> index 200168e..2601c61 100644
>> --- a/drivers/usb/dwc2/gadget.c
>> +++ b/drivers/usb/dwc2/gadget.c
>> [...]
>>
>>   	/*
>> -	 * Attempt to find a generic PHY, then look for an old style
>> -	 * USB PHY, finally fall back to pdata
>> +	 * If platform probe couldn't find a generic PHY or an old style
>> +	 * USB PHY, fall back to pdata
>>   	 */
>> -	phy = devm_phy_get(dev, "usb2-phy");
>> -	if (IS_ERR(phy)) {
>> -		uphy = devm_usb_get_phy(dev, USB_PHY_TYPE_USB2);
>> -		if (IS_ERR(uphy)) {
>> -			/* Fallback for pdata */
>> -			plat = dev_get_platdata(dev);
>> -			if (!plat) {
>> -				dev_err(dev,
>> -				"no platform data or transceiver defined\n");
>> -				return -EPROBE_DEFER;
>> -			}
>> -			hsotg->plat = plat;
>> -		} else
>> -			hsotg->uphy = uphy;
>> -	} else {
>> -		hsotg->phy = phy;
>> +	if (IS_ERR_OR_NULL(hsotg->phy) && IS_ERR_OR_NULL(hsotg->uphy)) {
>> +		plat = dev_get_platdata(dev);
>> +		if (!plat) {
>> +			dev_err(dev,
>> +			"no platform data or transceiver defined\n");
>> +			return -EPROBE_DEFER;
>> +		}
>> +		hsotg->plat = plat;
>> +	} else if (hsotg->phy) {
> You have changed the behavior here. Previously, the driver would work
> even if there were no phys or pdata defined. Now it will return
> -EPROBE_DEFER instead. Are you sure that won't break any existing
> platforms?
>
I don't really catch your meaning. Could you please point out where is 
the difference? Thanks .

In previous version, if there were no phy or usb_phy defined, 
devm_phy_get() and devm_usb_get_phy() both failed, then driver falls 
back to find pdata, if no pdata defined dev_get_platdata() returns NULL, 
then dwc2_gadget_init returns -EPROBE_DEFER and the dwc2_driver_probe 
fail. So I think, for the dwc2 driver without my patch, when 
CONFIG_USB_DWC2_PERIPHERAL or CONFIG_USB_DWC2_DUAL_ROLE selected, if 
there were no phys or pdata defined, the driver probe will also return 
-EPROBE_DEFER. And when only CONFIG_USB_DWC2_HOST selected, the previous 
version driver didn't care any thing about phy, in my patch it will try 
to find a phy when platform driver probe, but do not fail probe if there 
isn't a phy node.



  reply	other threads:[~2014-12-08  3:58 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-12-05 12:52 [PATCH v2 0/5] Yunzhi Li
2014-12-05 12:52 ` [PATCH v2 1/5] phy: add a driver for the Rockchip SoC internal USB2.0 PHY Yunzhi Li
2014-12-05 13:38   ` Romain Perier
2014-12-08  4:12     ` Yunzhi Li
2014-12-05 12:52 ` [PATCH v2 2/5] Documentation: bindings: add doc for the Rockchip usb PHY Yunzhi Li
2014-12-05 12:52 ` [PATCH v2 3/5] usb: dwc2: Add generic PHY framework support for dwc2 usb controler platform driver Yunzhi Li
2014-12-05 19:04   ` Paul Zimmerman
2014-12-08  3:58     ` Yunzhi Li [this message]
2014-12-08 19:46       ` Paul Zimmerman
2014-12-05 12:52 ` [PATCH v2 4/5] ARM: dts: add rk3288 usb PHY Yunzhi Li
2014-12-05 13:47   ` Romain Perier

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