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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org,
	linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org,
	"Jan Sebastian Götte" <linux@jaseg.net>,
	"Phil Reid" <preid@electromag.com.au>,
	"Nishad Kamdar" <nishadkamdar@gmail.com>
Subject: Re: [PATCH v1 1/2] fbtft: Rectify GPIO handling
Date: Fri, 16 Apr 2021 14:51:59 +0200	[thread overview]
Message-ID: <YHmIb2YrwfzZa7Wh@kroah.com> (raw)
In-Reply-To: <20210416123117.4993-1-andriy.shevchenko@linux.intel.com>

On Fri, Apr 16, 2021 at 03:31:16PM +0300, Andy Shevchenko wrote:
> The infamous commit c440eee1a7a1 ("Staging: fbtft: Switch to
> the GPIO descriptor interface") broke GPIO handling completely.
> It has already four commits to rectify and it seems not enough.
> In order to fix the mess here we:
> 
>   1) Set default to "inactive" for all requested pins
> 
>   2) Fix CS, RD, and WR pins polarity since it's active low and
>      GPIO descriptor interface takes it into consideration from
>      the Device Tree or ACPI
> 
>   3) Fix RESET pin polarity in the places missed by the commit
>      b918d1c27066 ("Staging: fbtft: Fix reset assertion when using gpio descriptor")
> 
>   4) Consolidate chip activation (CS assert) under default
>      ->reset() callback
> 
> To summarize the expectations about polarity for GPIOs:
> 
>    #RD			Low
>    #WR			Low
>    #CS			Low
>    #RESET		Low
>    DC or RS		High
>    RW			High
>    Data	0..15		High
> 
> See also Adafruit learning course [1] for the example of the schematics.
> 
> While at it, drop unneeded NULL checks, since GPIO API is tolerant to that.
> At the end, update TODO to mark this job eventually done.
> 
> [1]: https://learn.adafruit.com/adafruit-2-8-and-3-2-color-tft-touchscreen-breakout-v2/downloads

Shouldn't this be broken up into "one patch per thing" from your list
above?  Feels like you did a lot of different things all in the same
patch :(

thanks,

greg k-h

WARNING: multiple messages have this Message-ID (diff)
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: "Jan Sebastian Götte" <linux@jaseg.net>,
	linux-fbdev@vger.kernel.org,
	"Nishad Kamdar" <nishadkamdar@gmail.com>,
	linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org,
	dri-devel@lists.freedesktop.org,
	"Phil Reid" <preid@electromag.com.au>
Subject: Re: [PATCH v1 1/2] fbtft: Rectify GPIO handling
Date: Fri, 16 Apr 2021 14:51:59 +0200	[thread overview]
Message-ID: <YHmIb2YrwfzZa7Wh@kroah.com> (raw)
In-Reply-To: <20210416123117.4993-1-andriy.shevchenko@linux.intel.com>

On Fri, Apr 16, 2021 at 03:31:16PM +0300, Andy Shevchenko wrote:
> The infamous commit c440eee1a7a1 ("Staging: fbtft: Switch to
> the GPIO descriptor interface") broke GPIO handling completely.
> It has already four commits to rectify and it seems not enough.
> In order to fix the mess here we:
> 
>   1) Set default to "inactive" for all requested pins
> 
>   2) Fix CS, RD, and WR pins polarity since it's active low and
>      GPIO descriptor interface takes it into consideration from
>      the Device Tree or ACPI
> 
>   3) Fix RESET pin polarity in the places missed by the commit
>      b918d1c27066 ("Staging: fbtft: Fix reset assertion when using gpio descriptor")
> 
>   4) Consolidate chip activation (CS assert) under default
>      ->reset() callback
> 
> To summarize the expectations about polarity for GPIOs:
> 
>    #RD			Low
>    #WR			Low
>    #CS			Low
>    #RESET		Low
>    DC or RS		High
>    RW			High
>    Data	0..15		High
> 
> See also Adafruit learning course [1] for the example of the schematics.
> 
> While at it, drop unneeded NULL checks, since GPIO API is tolerant to that.
> At the end, update TODO to mark this job eventually done.
> 
> [1]: https://learn.adafruit.com/adafruit-2-8-and-3-2-color-tft-touchscreen-breakout-v2/downloads

Shouldn't this be broken up into "one patch per thing" from your list
above?  Feels like you did a lot of different things all in the same
patch :(

thanks,

greg k-h
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  parent reply	other threads:[~2021-04-16 12:52 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-16 12:31 [PATCH v1 1/2] fbtft: Rectify GPIO handling Andy Shevchenko
2021-04-16 12:31 ` Andy Shevchenko
2021-04-16 12:31 ` [PATCH v1 2/2] fbtft: Don't spam logs when probe is deferred Andy Shevchenko
2021-04-16 12:31   ` Andy Shevchenko
2021-04-16 12:51 ` Greg Kroah-Hartman [this message]
2021-04-16 12:51   ` [PATCH v1 1/2] fbtft: Rectify GPIO handling Greg Kroah-Hartman
2021-04-16 13:37   ` Andy Shevchenko
2021-04-16 13:37     ` Andy Shevchenko
2021-04-16 13:41     ` Andy Shevchenko
2021-04-16 13:41       ` Andy Shevchenko
2021-04-16 14:20   ` Andy Shevchenko
2021-04-16 14:20     ` Andy Shevchenko

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