From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 14895C83018 for ; Tue, 1 Dec 2020 16:44:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AE410208C3 for ; Tue, 1 Dec 2020 16:44:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=goldelico.com header.i=@goldelico.com header.b="e427UWmK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728652AbgLAQou (ORCPT ); Tue, 1 Dec 2020 11:44:50 -0500 Received: from mo4-p01-ob.smtp.rzone.de ([85.215.255.54]:27478 "EHLO mo4-p01-ob.smtp.rzone.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728345AbgLAQot (ORCPT ); Tue, 1 Dec 2020 11:44:49 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; t=1606840917; s=strato-dkim-0002; d=goldelico.com; h=To:References:Message-Id:Cc:Date:In-Reply-To:From:Subject: X-RZG-CLASS-ID:X-RZG-AUTH:From:Subject:Sender; bh=Pnd9RyOkaw5mK5HLX0+EUHATeM6rpD28J4eLpJ4iBb0=; b=e427UWmKAIjAebUsji6LShlrpMdBLHOddM79UGQG5RG7RyO2aDTzOhlZOspd1vKwSC PE9JoFsO4qGKhrCqrkn7cWUT1X3ECGWvMHvlt18uYLvQxcB4LW5SInunkEE0iDA7jNk/ PjYagA+cG+5nC2SXj+L1QCP8IEwk3G11IhmxpuR5FnDLsA/YJNo3Orxm1KAi6m7BtAxO JuZaUvHQ52EHC+hTZE3tmrTGXiJ/p5K3KvanIbl5KjBcthj801vclDtKm5McejEVhQ8F 5BY6DaZslRMU1Y4Wk7vzM4dY6JqvjlDSEOhaz1AZ64bCMEfq5IXjcW1V+996ztf6jPnd E+/Q== X-RZG-AUTH: ":JGIXVUS7cutRB/49FwqZ7WcJeFKiMgPgp8VKxflSZ1P34KBj7wpz8NMGH/vrwDuo6A==" X-RZG-CLASS-ID: mo00 Received: from imac.fritz.box by smtp.strato.de (RZmta 47.3.4 DYNA|AUTH) with ESMTPSA id N02faawB1GftVWA (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (curve X9_62_prime256v1 with 256 ECDH bits, eq. 3072 bits RSA)) (Client did not present a certificate); Tue, 1 Dec 2020 17:41:55 +0100 (CET) Subject: Re: [BUG] SPI broken for SPI based panel drivers Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) Content-Type: text/plain; charset=us-ascii From: "H. Nikolaus Schaller" In-Reply-To: <20201201162035.GK5239@sirena.org.uk> Date: Tue, 1 Dec 2020 17:41:54 +0100 Cc: Linus Walleij , Sven Van Asbroeck , kernel list , Laurent Pinchart , Discussions about the Letux Kernel Content-Transfer-Encoding: quoted-printable Message-Id: <8D0E8CDA-96EA-4900-B5B2-0AD371EAD046@goldelico.com> References: <2D7916FA-678F-4236-B478-C953CADF2FFA@goldelico.com> <4AC29229-9542-4E77-B993-217E29C7E209@goldelico.com> <20201201121620.GB5239@sirena.org.uk> <20201201162035.GK5239@sirena.org.uk> To: Mark Brown X-Mailer: Apple Mail (2.3124) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Am 01.12.2020 um 17:20 schrieb Mark Brown : >=20 > On Tue, Dec 01, 2020 at 03:20:12PM +0100, Linus Walleij wrote: >=20 >> The reason why I shoot in the dark to convert all SPI >> drivers to use GPIO descriptors instead of the global >> GPIO numberspace is detailed in drivers/gpio/TODO >> so I will not repeat it here. >=20 >> I don't know if much can be done about it other than >> having better programmers than me at the task. Or >> less tired when they write the patch. etc. >=20 > 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.=