linux-kernel - Re: [PATCH 2/4] gpio: davinci: Handle the return value of davinci_gpio_irq

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Message-ID: <02965359-ecf1-b934-6b7a-87162d7d00a4@ti.com>
Date:   Thu, 20 Jul 2017 16:34:42 -0500
From:   Grygorii Strashko <grygorii.strashko@...com>
To:     Johan Hovold <johan@...nel.org>, Keerthy <j-keerthy@...com>
CC:     <linus.walleij@...aro.org>, <ssantosh@...nel.org>,
        <devicetree@...r.kernel.org>, <nsekhar@...com>,
        <linux-kernel@...r.kernel.org>, <linux-gpio@...r.kernel.org>,
        <robh+dt@...nel.org>, <linux-arm-kernel@...ts.infradead.org>,
        <fcooper@...com>
Subject: Re: [PATCH 2/4] gpio: davinci: Handle the return value of
 davinci_gpio_irq_setup function



On 07/20/2017 05:05 AM, Johan Hovold wrote:
> On Thu, Jul 20, 2017 at 03:32:27PM +0530, Keerthy wrote:
>> On Thursday 20 July 2017 03:20 PM, Johan Hovold wrote:
>>> On Thu, Jul 20, 2017 at 02:40:37PM +0530, Keerthy wrote:
>>>> On Thursday 20 July 2017 12:14 PM, Keerthy wrote:
>>>>> On Wednesday 19 July 2017 04:40 PM, Johan Hovold wrote:
> 
>>>>>> There's a separate but related bug here too as the clk_prepare_enable()
>>>>>> in davinci_gpio_irq_setup() is never balanced on driver unbind.
>>>>>
>>>>> Yes Johan. I will send that as a separate patch.
>>>>
>>>> This is already fixed in the latest kernel:
>>>>
>>>> commit 6dc0048cff988858254fcc26becfc1e9753efa79
>>>> Author: Arvind Yadav <arvind.yadav.cs@...il.com>
>>>> Date:   Tue May 23 14:48:57 2017 +0530
>>>
>>> That change only handles errors in davinci_gpio_irq_setup() (i.e. during
>>> probe) and not the imbalance at driver unbind that I was referring to.
>>
>> Okay got it. One more clk_unprepare_disable() call needs to be there in
>> probe err path.
> 
> No, you need to balance it on driver unbind, that is, in a new remove()
> callback.
> 

Sry, but manual driver unbind for this driver is really smth unexpected ;(
So, I'm not sure if it need to be implemented and even yes - it should not be
a part of this patch. Probably, smth like "convert driver to be a module".

By the way, I've tried to unbind gpio-omap, result - failure (expected),
as unbind does not take into account module refcnt state.


-- 
regards,
-grygorii