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Subject: Re: [REGRESSION][BISECTED] i.MX6 pinctrl hogs stopped working
From:   Richard Fitzgerald <rf@opensource.cirrus.com>
To:     =?UTF-8?Q?Mika_Penttil=c3=a4?= <mika.penttila@nextfour.com>,
        <linus.walleij@linaro.org>
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        <patches@opensource.cirrus.com>
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Date:   Fri, 27 Apr 2018 10:13:21 +0100
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On 17/04/18 09:50, Richard Fitzgerald wrote:
> On 10/04/18 19:33, Mika Penttilä wrote:
>>
>>
>> On 10.04.2018 13:21, Richard Fitzgerald wrote:
>>> On 04/04/18 06:33, Mika Penttilä wrote:
>>>> Hi!
>>>>
>>>> Reverting this made the hogs on a i.MX6 board work again. :
>>>>
>>>>
>>>> commit b89405b6102fcc3746f43697b826028caa94c823
>>>> Author: Richard Fitzgerald <rf@opensource.cirrus.com>
>>>> Date:   Wed Feb 28 15:53:06 2018 +0000
>>>>
>>>>       pinctrl: devicetree: Fix dt_to_map_one_config handling of hogs
>>>>
>>>>
>>>>
>>>> --Mika
>>>>
>>>
>>> I think you should check whether the bug is with the i.MX6 driver
>>> relying on the previous buggy behaviour of pinctrl. I haven't got
>>> i.MX6 hardware to test myself.
>>>
>>> The bug I fixed in that patch was that when pinctrl is probing a
>>> pinctrl driver it would try to apply all the pinctrl settings
>>> listed in a dt node to the pinctrl driver it is probing instead
>>> of the pinctrl drivers they actually refer to. This was a bug
>>> introduced by an earlier patch (which unfortunately I forgot to
>>> include a fixes line reference to)
>>>
>>>    pinctrl: core: Use delayed work for hogs
>>>
>>> So if a pinctrl driver "A" had a dependency on another pinctrl
>>> driver "B" those dependencies wouldn't be properly created because
>>> all the "B" pinctrl DT entries would be attempted against "A"
>>> instead of "B". This caused failures if a pinctrl driver had a
>>> dependency on another pinctrl driver, of if creating a pinctrl
>>> driver that is a child of an MFD and that MFD has dependencies
>>> on another pinctrl driver.
>>>
>>
>> Hard to say, but the kernel/dts has worked ok for 3+ years, from 3.17 
>> until 4.17-rc. Nothing fancy, just normal hogs, in two groups.
>> Can send you relevant pieces of DT if interested.
>>
>> --Mika
>>
> 
> Tell me where in the kernel tree the the dts files and the source for
> the pinctrl driver that uses them and which dts node, and I will look
> at what the driver is doing.

Hi,

Sorry, I have been very busy and haven't had time to look at the i.MX6
driver yet.