Re: [PATCH v5] i2c: imx: make bus recovery through pinctrl optional

From	Leo Li <pku.leo@gmail.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v5] i2c: imx: make bus recovery through pinctrl optional
Date	2016-09-12 18:30 +0200
Message-ID	<sgChj-5GQ-3@gated-at.bofh.it> (permalink)
References	(5 earlier) <sfgiS-3lF-21@gated-at.bofh.it> <sfhoB-3WL-11@gated-at.bofh.it> <sfxjI-5u3-25@gated-at.bofh.it> <sfzOy-71n-23@gated-at.bofh.it> <sguMN-LC-13@gated-at.bofh.it>
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On Mon, Sep 12, 2016 at 3:21 AM, Lothar Waßmann <LW@karo-electronics.de> wrote:
> Hi,
>
> On Fri, 9 Sep 2016 14:37:12 -0500 Leo Li wrote:
>> On Fri, Sep 9, 2016 at 11:51 AM, Stefan Agner <stefan@agner.ch> wrote:
>> > On 2016-09-08 16:57, Leo Li wrote:
> [...]
>> >> people fix problem that they don't really care by deliberately enlarge
>> >> the problem.  That's why we don't panic() on any error we found.  For
>> >> those who do care about the bus recovery, they can get the information
>> >> from the console.
>> >
>> > IMHO, it is just stupid to ignore errors and then let the developer
>> > later on trace back what the initial issue was. Error out early is a
>> > common sense software design principle...
>> >
>> > I am not asking for a panic(), I am just suggesting to only ignore
>> > pinctrl if it returns -ENODEV, the case you care are about.
>>
>> It was just an analogy for enlarging the problem for getting
>> attention.  But you probably thought that it was not enlarging the
>> problem as you think pinctrl is required by the driver instead of an
>> optional thing.
>>
> The I2C bus recovery is a feature which is not used during normal
> operation and you won't find that it's not working unless something
> unusual happens (probably only in a productive environment). It may even
> be hard to trigger a condition to test the feature.
> Thus IMO it is vital that the driver complains loudly if something is
> missing to make this feature work if requested.

I agree.  A message is already added in this patch to mention that bus
recovery is not supported due to pinctrl when there is a problem.

Regards,
Leo

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Re: [PATCH v5] i2c: imx: make bus recovery through pinctrl optional Stefan Agner <stefan@agner.ch> - 2016-09-09 19:00 +0200
  Re: [PATCH v5] i2c: imx: make bus recovery through pinctrl optional Leo Li <pku.leo@gmail.com> - 2016-09-09 21:40 +0200
    Re: [PATCH v5] i2c: imx: make bus recovery through pinctrl optional Stefan Agner <stefan@agner.ch> - 2016-09-09 22:50 +0200
      Re: [PATCH v5] i2c: imx: make bus recovery through pinctrl optional Uwe Kleine-König          <u.kleine-koenig@pengutronix.de> - 2016-09-09 23:00 +0200
        Re: [PATCH v5] i2c: imx: make bus recovery through pinctrl optional Leo Li <pku.leo@gmail.com> - 2016-09-12 18:50 +0200
    Re: [PATCH v5] i2c: imx: make bus recovery through pinctrl optional Lothar Waßmann <LW@KARO-electronics.de> - 2016-09-12 10:30 +0200
      Re: [PATCH v5] i2c: imx: make bus recovery through pinctrl optional Leo Li <pku.leo@gmail.com> - 2016-09-12 18:30 +0200

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