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From: "Vokáč Michal" <Michal.Vokac@ysoft.com>
To: Fabio Estevam <festevam@gmail.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
	Shawn Guo <shawnguo@kernel.org>,
	Fabio Estevam <fabio.estevam@nxp.com>,
	Rob Herring <robh+dt@kernel.org>,
	"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
	<devicetree@vger.kernel.org>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	"linux-fbdev@vger.kernel.org" <linux-fbdev@vger.kernel.org>
Subject: Re: [RESEND PATCH v2 3/3] ARM: dts: imx28-cfa10036: Fix the reset gpio signal polarity
Date: Tue, 9 Oct 2018 13:18:24 +0000	[thread overview]
Message-ID: <221a185c-19fc-cc89-49b1-aa77fb1f0e41@ysoft.com> (raw)
In-Reply-To: <CAOMZO5DdV9Sm9z6wX8e4LTvbokjnOMqtgOJQOvVvysVvzaBKGw@mail.gmail.com>

On 9.10.2018 14:36, Fabio Estevam wrote:
> Hi Michal,
> 
> On Tue, Oct 9, 2018 at 5:30 AM Vokáč Michal <Michal.Vokac@ysoft.com> wrote:
> 
>> Sorry for the inconvenience :( Lesson learned..
>>
>> So in other words (no offense): broken drivers need to stay broken because
>> users may already get used to the broken behavior?
> 
> In order to keep the old dtb's working you could introduce a new
> property (like reset-gpio-active-low, for example).
> 
> Then the driver behavior can be made untouched for the old dtb's and
> only new dtb's with this new property would have the correct GPIO
> reset behavior.

Thank you very much Fabio!
I saw these xxx-active-low/high properties in many device tree
sources wondering why the heck people use them when they could
use GPIO_ACTIVE_LOW/HIGH. And this is the explanation.

And I feel like an idiot once again: git grep -l "reset-active-low"
first hit is:

  Documentation/devicetree/bindings/display/ssd1307fb.txt

Oooops.
The weird thing is that usage of reset-active-low is documented
in the example but it is not implemented.

So the patch no.2 should be reverted and patch no.3 not applied at all.

I will prepare a new patch utilizing the reset-active-low property.

Again, sorry for the troubles and thank you for your comments.
Michal

  reply	other threads:[~2018-10-09 13:18 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20180927092738epcas5p28c53516b73fe7747133914f40c84d6c4@epcas5p2.samsung.com>
2018-09-27  9:24 ` [RESEND PATCH v2 1/3] video: ssd1307fb: Use gpiod_set_value_cansleep() for reset Michal Vokáč
2018-09-27  9:24   ` [RESEND PATCH v2 2/3] video: ssd1307fb: Do not hard code active-low reset sequence Michal Vokáč
2018-10-08 10:53     ` Bartlomiej Zolnierkiewicz
2018-09-27  9:24   ` [RESEND PATCH v2 3/3] ARM: dts: imx28-cfa10036: Fix the reset gpio signal polarity Michal Vokáč
2018-10-08 11:45     ` Vokáč Michal
2018-10-09  0:20       ` Shawn Guo
2018-10-09  7:51         ` Bartlomiej Zolnierkiewicz
2018-10-09  8:29           ` Vokáč Michal
2018-10-09 12:36             ` Fabio Estevam
2018-10-09 13:18               ` Vokáč Michal [this message]
2018-10-09 13:30                 ` Bartlomiej Zolnierkiewicz
2018-10-08 10:53   ` [RESEND PATCH v2 1/3] video: ssd1307fb: Use gpiod_set_value_cansleep() for reset Bartlomiej Zolnierkiewicz

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