From mboxrd@z Thu Jan  1 00:00:00 1970
From: "andriy.shevchenko" <andriy.shevchenko@linux.intel.com>
Subject: Re: Re: [PATCH] pinctrl: intel: Implements gpio free function
Date: Sat, 23 Mar 2019 18:48:10 +0200
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To: "zhuchangchun@cvte.com" <zhuchangchun@cvte.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>, "linus.walleij" <linus.walleij@linaro.org>, linux-gpio <linux-gpio@vger.kernel.org>, linux-kernel <linux-kernel@vger.kernel.org>, hendychu <hendychu@aliyun.com>
List-Id: linux-gpio@vger.kernel.org

On Sat, Mar 23, 2019 at 02:51:52PM +0800, zhuchangchun@cvte.com wrote:
> On Fri, Mar 22, 2019 at 11:14:14AM +0800, zhuchangchun@cvte.com wrote:

> >    From above,you can kown when you export a GPIO ,it will do request,
> >
> >    and there will set TX and RX register at the time same time.
> >
> >    when you try to set direction in and set value, TX register value can
> >    roll back
> >
> >    the value,but RX register was not set, so who will set RX value back??
>  
> I think you are looking at some older code. There is now function
> __intel_gpio_set_direction() that is supposed to set both buffers
> depending on the direction. It was introduced with commit 17fab473693e
> ("pinctrl: intel: Set pin direction properly").
> 
> 
> --> Yes ,I see the latest master branch, the __intel_gpio_set_direction will
> set RX and TX, but I still think we need to implement free function,cause
> it will help many other engineers,especailly for some manufactories use some
> module,and this modules embeded its own driver but not can be modified,
> if they want use the gpio control the module, they may meet the same problem.

What problem?
Is it reproducible on latest vanilla kernel?

-- 
With Best Regards,
Andy Shevchenko