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From: Mark Brown <broonie@kernel.org>
To: "H. Nikolaus Schaller" <hns@goldelico.com>
Cc: Linus Walleij <linus.walleij@linaro.org>,
	Sven Van Asbroeck <thesven73@gmail.com>,
	kernel list <linux-kernel@vger.kernel.org>,
	Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	Discussions about the Letux Kernel 
	<letux-kernel@openphoenux.org>
Subject: Re: [BUG] SPI broken for SPI based panel drivers
Date: Tue, 1 Dec 2020 17:11:53 +0000	[thread overview]
Message-ID: <20201201171153.GM5239@sirena.org.uk> (raw)
In-Reply-To: <8D0E8CDA-96EA-4900-B5B2-0AD371EAD046@goldelico.com>

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On Tue, Dec 01, 2020 at 05:41:54PM +0100, H. Nikolaus Schaller wrote:
> > Am 01.12.2020 um 17:20 schrieb Mark Brown <broonie@kernel.org>:

> > I think the problem here is more to do with where we started than where
> > we're going or how we got there - things have been glued together or
> > happened to work in ways that mean I'm not sure we reasonably understand
> > the situation we started from or all the requirements it has.  As you
> > say I'm not sure anything beyond throwing the API away and starting
> > afresh would really help here, but that's not really how we tend to do
> > things for a bunch of very good reasons.

> I think the key problem is GPIO_ACTIVE_HIGH 0 and GPIO_ACTIVE_LOW 1
> in device tree blobs. But that is so fundamental that we have to live with it.
> So I guess that even a new API from scratch wouldn't improve that.

Yeah, that's definitely part of it - more generally there's multiple
places trying to determine if the signal is inverted with different
interactions/expectations.  Having it in an ABI definitely contributes a
lot to causing trouble though.

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  reply	other threads:[~2020-12-01 17:13 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-30 19:03 [BUG] SPI broken for SPI based panel drivers H. Nikolaus Schaller
2020-11-30 20:13 ` Sven Van Asbroeck
2020-11-30 20:22   ` Sven Van Asbroeck
2020-12-01  8:59   ` H. Nikolaus Schaller
2020-12-01 12:16     ` Mark Brown
2020-12-01 14:05       ` H. Nikolaus Schaller
2020-12-01 14:20         ` Linus Walleij
2020-12-01 14:34           ` Sven Van Asbroeck
2020-12-01 14:35           ` H. Nikolaus Schaller
2020-12-01 15:52             ` Sven Van Asbroeck
2020-12-01 16:46               ` H. Nikolaus Schaller
2020-12-01 16:10             ` Sven Van Asbroeck
2020-12-01 16:39               ` H. Nikolaus Schaller
2020-12-01 16:53                 ` Sven Van Asbroeck
2020-12-01 17:10                   ` H. Nikolaus Schaller
2020-12-01 18:43                     ` Sven Van Asbroeck
2020-12-02 12:19                       ` Mark Brown
2020-12-04 10:08                       ` H. Nikolaus Schaller
2020-12-04 13:46                         ` Sven Van Asbroeck
2020-12-04 16:49                           ` H. Nikolaus Schaller
2020-12-04 19:19                             ` Sven Van Asbroeck
2020-12-04 21:31                               ` H. Nikolaus Schaller
2020-12-05  0:25                             ` Linus Walleij
2020-12-05  7:04                               ` H. Nikolaus Schaller
2020-12-09  8:04                                 ` Andreas Kemnade
2020-12-09  8:40                                   ` H. Nikolaus Schaller
2020-12-09  8:38                                 ` Linus Walleij
2020-12-09  8:45                                   ` H. Nikolaus Schaller
2020-12-01 22:51                     ` Linus Walleij
2020-12-01 16:44               ` [Letux-kernel] " Andreas Kemnade
2020-12-01 16:51                 ` H. Nikolaus Schaller
2020-12-01 16:52                 ` H. Nikolaus Schaller
2020-12-01 16:55                 ` Sven Van Asbroeck
2020-12-01 16:20           ` Mark Brown
2020-12-01 16:41             ` H. Nikolaus Schaller
2020-12-01 17:11               ` Mark Brown [this message]
2020-12-01 12:41     ` Sven Van Asbroeck
2020-12-01 13:32       ` H. Nikolaus Schaller
2020-12-01 14:08         ` Sven Van Asbroeck
2020-12-01 15:33           ` Mark Brown
2020-12-05 20:57   ` Pavel Machek
2020-12-07 13:43     ` Mark Brown

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