linux-kernel - Re: [PATCH v6 2/2] phy: rockchip-inno-usb2: add a new driver for Rockchip usb2phy

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Message-ID: <f70f9c49-9eb7-5dc9-4ff1-eab1481ad66a@rock-chips.com>
Date:	Tue, 21 Jun 2016 17:27:33 +0800
From:	Frank Wang <frank.wang@...k-chips.com>
To:	Heiko Stübner <heiko@...ech.de>
Cc:	Guenter Roeck <linux@...ck-us.net>,
	Guenter Roeck <groeck@...gle.com>,
	Guenter Roeck <groeck@...omium.org>,
	Douglas Anderson <dianders@...omium.org>, jwerner@...omium.org,
	Kishon Vijay Abraham I <kishon@...com>, robh+dt@...nel.org,
	pawel.moll@....com, mark.rutland@....com,
	ijc+devicetree@...lion.org.uk, Kumar Gala <galak@...eaurora.org>,
	linux-kernel@...r.kernel.org, devicetree@...r.kernel.org,
	linux-usb@...r.kernel.org, linux-rockchip@...ts.infradead.org,
	Ziyuan Xu <xzy.xu@...k-chips.com>,
	Kever Yang <kever.yang@...k-chips.com>,
	Tao Huang <huangtao@...k-chips.com>, william.wu@...k-chips.com,
	frank.wang@...k-chips.com
Subject: Re: [PATCH v6 2/2] phy: rockchip-inno-usb2: add a new driver for
 Rockchip usb2phy

Hi Heiko,

On 2016/6/21 17:05, Heiko Stübner wrote:
> Hi Frank,
>
> Am Dienstag, 21. Juni 2016, 15:52:45 schrieb Frank Wang:
>> On 2016/6/20 12:56, Guenter Roeck wrote:
>>> On Sun, Jun 19, 2016 at 8:32 PM, Frank Wang <frank.wang@...k-chips.com>
> wrote:
>>>>> Turns out my problem was one of terminology. Using "suspend" and
>>>>> "resume" to me suggested the common use of suspend and resume
>>>>> functions. That is not the case here. After mentally replacing
>>>>> "suspend" with "power_off" and "resume" with "power_on", you are
>>>>> right, no problem exists. Sorry for the noise.
>>>>>
>>>>> Maybe it would be useful to replace "resume" with "power_on" and
>>>>> "suspend" with "power_off" in the function and variable names to
>>>>> reduce confusion and misunderstandings.
>>>>>
>>>>> Thanks,
>>>>> Guenter
>>>> Well, it does have a bits confusion, however, the phy-port always just
>>>> goes
>>>> to suspend and resume mode (Not power off and power on) in a fact. So
>>>> must
>>>> it be renamed?
>>> Other phy drivers name the functions _power_off and _power_on and
>>> avoid the confusion. The callbacks are named .power_off and .power_on,
>>> which gives a clear indication of its intended purpose. Other drivers
>>> implementing suspend/resume (such as the omap usb phy driver) tie
>>> those functions not into the power_off/power_on callbacks, but into
>>> the driver's suspend/resume callbacks. At least the omap driver has
>>> separate power management functions.
>>>
>>> Do the functions _have_ to be renamed ? Surely not. But, if the
>>> functions are really suspend/resume functions and not
>>> power_off/power_on functions, maybe they should tie to the
>>> suspend/resume functions and not register themselves as
>>> power_off/power_on functions ?
>> As Guenter mentioned above,  I doped out two solutions, one is that keep
>> current process but renaming *_resume/*_suspend to
>> *_power_on/*_power_off;
> in a way, naming stuff "power_off", "power_on" actually matches. For one, the
> phy-block goes from unusable to usable by usb-devices and also will power-on a
> phy-supply regulator (often named vcc_host* on Rockchip boards) from the phy-
> core.
>
>> another is that do not assign power_on/power_off
>> functions for phy_ops at phy creating time, then, shorten
>> _SCHEDULE_DELAY_ delay time less that 10 Seconds, and the phy-port
>> suspend/resume mechanism depend on _sm_work_ completely.
> Which in turn would mean that we would always depend on a fully controllable
> phy block. Right now it seems, rk3036, rk3228, rk3368 (probably forgot some)
> have the same type of phy, but with at least the unplug-detection missing.
> In its current form the driver can very well support those (later on) by
> simply working statically (only acting on phy_power callbacks and not going to
> suspend on its own).
>
> Also having the work running in 10-second intervall seems wasteful.
>
>> So which is the better way from your view? or would you like to give
>> other unique perceptions please?
> As obvious from the above, I would prefer just renaming the functions :-)
>
> Heiko
>

Got it, thanks for your comments. I am going to correct and send out a 
new version later today, so sorry for trouble you to sign 'Reviewed-by' 
again if no any other issues.


BR.
Frank