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=-2.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 DC780C64E90 for ; Tue, 1 Dec 2020 12:42:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7792F2086A for ; Tue, 1 Dec 2020 12:42:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="pGSpIf1Z" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731073AbgLAMmd (ORCPT ); Tue, 1 Dec 2020 07:42:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57618 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727055AbgLAMmc (ORCPT ); Tue, 1 Dec 2020 07:42:32 -0500 Received: from mail-ua1-x92a.google.com (mail-ua1-x92a.google.com [IPv6:2607:f8b0:4864:20::92a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DB030C0613D4 for ; Tue, 1 Dec 2020 04:41:45 -0800 (PST) Received: by mail-ua1-x92a.google.com with SMTP id n18so514721ual.9 for ; Tue, 01 Dec 2020 04:41:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=v43BG8WdmWcru6537pQrqF+UFky2hIVmNYym4F7zcys=; b=pGSpIf1ZUnp/ObvsAXOZwAFXdIH0M5a7ClfrjwfFm0yfyM1SGO61i8H7bdwHdvByGF 712YrLSz29NNtaxRRjpMS9ZbBICzmZZLnSrSGtbCFsQX8f2zh6pQoKNhCmAPFUWIPyKF rHI7FJ5uJUrhU/OvjudNu2VmwEsVMsTRnGEH7/neChuMm7vJPbGexsxrr2aJx2JKehVc 8Z55l9Bq5Zbx50SgMmOmHyf7utUSyK5cM5OPdYtT25Ya8B7PEBxm4EQiDWaw0qvkDzbk IgZZ1ubcYue4LH5EqPqDhP3Kv+Vm4ITfaLMSZ4uiJvn026//DqU1K0jjyl2OxUtKIpXR FLpA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=v43BG8WdmWcru6537pQrqF+UFky2hIVmNYym4F7zcys=; b=Pse4cH5azZ0MjrC8d3N3G4hGXtHQv8O6b7FzNEG010rVpg5jMQeooS382qK4ZowVny gE6BjMZnwj+pYpcpse4nvMZYHwXLzMWREUsUuj6F/ypjp2RIUnKCl0fOATVrgAorD0sy dzTNS5/tsdacHytopcmzIOnttKed+jV9bmHnEkgRVc3hUF/w0DWFxvTuxfwLreCd+anS FI532W3MqC657MJELzGtt7lkLFRQKCbSPelAJNMnn0m4ybwc9StQ/luePtqyPT7xOlgS cWC47V1bVnHvuf/lHu3jwE9t9xxGq3oEzV9A/q/WupE3RhPSWMGIVqJoDxUofRE1xuMe gxJA== X-Gm-Message-State: AOAM533INjUyXzdMIbZgjl1VVV74GXwXz0X5Yh3fcwcGyY1mX6G/vxmv scAUTVgxNeQxDk6gtw3pscmDcRnRPLdxtTPC6rjfdpXotm8= X-Google-Smtp-Source: ABdhPJx7/9m5qfZKrRGotGWEfjI20997wgUO0Nj77ZMeYLf3xBqE/PcapQUroLqXNt26KQBHIpm7WfXEIrBCKaPXaoE= X-Received: by 2002:ab0:281a:: with SMTP id w26mr2358094uap.49.1606826504834; Tue, 01 Dec 2020 04:41:44 -0800 (PST) MIME-Version: 1.0 References: <2D7916FA-678F-4236-B478-C953CADF2FFA@goldelico.com> <4AC29229-9542-4E77-B993-217E29C7E209@goldelico.com> In-Reply-To: <4AC29229-9542-4E77-B993-217E29C7E209@goldelico.com> From: Sven Van Asbroeck Date: Tue, 1 Dec 2020 07:41:33 -0500 Message-ID: Subject: Re: [BUG] SPI broken for SPI based panel drivers To: "H. Nikolaus Schaller" Cc: Linus Walleij , Mark Brown , kernel list , Laurent Pinchart , Discussions about the Letux Kernel Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 1, 2020 at 4:04 AM H. Nikolaus Schaller wrote: > > Then it should not have been applied to mainline but fully worked out and tested. > That would be a reasonable expectation of a product. But Linux isn't a product, it's a hugely complex, shared system, which may form the basis of your product. The core maintainers aren't superhuman, nor do they have access to the 1000s of configurations and devices where Linux runs or will run. They do their very best, but if every change had to be 100% tested in every possible configuration, then few things could ever change, and Linux would slow down to a snail's pace. When your product is based on Linux and you pull a newer version off kernel.org, it's not unreasonable to expect the occasional breakage. In my case, when I moved from 5.7 to 5.9, some of the things that broke were my network chip, and most SPI drivers. That was a bad day, most pulls are trouble-free. I believe LTSes are more stable than 'stable releases' which are in turn more stable than RCs. The choice involves a trade-off between features, security and stability. When you do run into a breakage, complaining on the mailing list is good, but posting a fix is better :) This is my layman's understanding of the situation, I'm just a user and not a maintainer. > > > >> > >> What should we do? Hopefully I have some time this week to look into your breakage, I may get overtaken by someone much more knowledgeable than me on spi-gpio.