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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B444AE784B0 for ; Mon, 2 Oct 2023 09:43:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=nCA/kjg3Ow7TNWT5lweUdD7K1xQtO/vVSFltRLZhy3k=; b=m59TySfmEnuhxe O1v2XaEwzqN1sZKdpRSRGaxqN5lx2HE4YWj2g2qcWpGLPq5h3/VHMsVXC5ULiFNZenUNA0lL23pNS R1GZ0G+CH/V7ACvgLQTYabeyb8IdBsm0aaOH13R7Whkv+cxiw3yPwZIaIcOI7cc2enJjwq8R01T3Y fyAcjnZCIVMc8c9QAuLwRVT+JpgbL1wwPm47ppEu9vI8TsstsgKlhd8eYqM8Jgd717ddgtwC8Q0vV 5moq692QL7F1td2CEC2XpmGLM9JUMlSRDG+oboisCgtu3bYI2IEtavAmgwOcI0jzwFyq2OqEE1kZE ro1q30dGrsPfP+8qL/Mw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qnFS0-00CFev-2s; Mon, 02 Oct 2023 09:42:52 +0000 Received: from mail-pl1-x630.google.com ([2607:f8b0:4864:20::630]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qnFRx-00CFcm-27 for linux-arm-kernel@lists.infradead.org; Mon, 02 Oct 2023 09:42:51 +0000 Received: by mail-pl1-x630.google.com with SMTP id d9443c01a7336-1c328b53aeaso146011415ad.2 for ; Mon, 02 Oct 2023 02:42:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1696239767; x=1696844567; darn=lists.infradead.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=FKWths37TuzuxqmK8rBu5qlLw0gJAvBT78PBFmf+dIk=; b=dGFkYSRbVR5DKfGthvqQE6cTlrHDp0wP0oQhLhsLBnDKK/LS21fpXB1yUhESHbbP/V GvqTgz4NPfbFLppsBtzpReCBm+Ux4C0K8/J84RaU7Ahi2XNjQaxYuzsFDnVMA38Bt4jM ZhXJiEK7pSLc1uHfFnliix2r8A+iGGlgko/VkKB0l4PLp8pdrYDEOFhLITq0flsKSsfa iQ9RN6VgzRihfW541fg5We1BULl/grcuStDQUEt2GcBKcWYyvMwGNfLFfjGvlVxvKKzo fzo3mcohNFjtJBCDLHnhUujOwfSar4Go3GFgQFL8kZQnK+ap3/5KjuIH2m6JbL7KeeFV 6Rpw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1696239767; x=1696844567; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=FKWths37TuzuxqmK8rBu5qlLw0gJAvBT78PBFmf+dIk=; b=sW1uP1jxVFSHA1tQyYt3mohryDR0HleVpI+Lk7ETAIwWiQy1gLRGE4agWAPCa0bRQo ukwArA6iqtDehGjeEZaKIlRrE1v4eUkugi8nxWh0HQKImbLeTV7NQ8LqzUlPJZi5ht6T DLeta03UUj22RW2cVLEkZehCH/6N+zHQ19jl906dl97wO32f1KozyCNYxgeKeQuYfYuJ zuEJ+pRfq9aLNHxdMqeVkwxMiQGMiC1cW3QOuQSqc47+I/sH6AK1aQBcsGeGaD/GRHiX sfuN0NkrITe4iDKPiVGYaEhXSzsseVwLcCSTd7fPUiKBw2J3r0a63mtfEAvcxZMLjU4k weqA== X-Gm-Message-State: AOJu0Yz65LA8gm/mQnbHXVGfyIn4KMy1OycBsDfSGDv/+R1cv8dHBi8t M095bbN8s90K24QoJPsAIwM= X-Google-Smtp-Source: AGHT+IGJRJII6BjYEQve6vgOr3S4LQS11bujKYeGSJcS7jCV7mIKL7MxFT3lrUmNtDNzIvbuu1uF2A== X-Received: by 2002:a17:902:d2ce:b0:1c3:ed30:ce0a with SMTP id n14-20020a170902d2ce00b001c3ed30ce0amr14783738plc.19.1696239766662; Mon, 02 Oct 2023 02:42:46 -0700 (PDT) Received: from sol ([118.209.204.34]) by smtp.gmail.com with ESMTPSA id jj7-20020a170903048700b001c73701bd17sm7901033plb.4.2023.10.02.02.42.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 02 Oct 2023 02:42:46 -0700 (PDT) Date: Mon, 2 Oct 2023 17:42:39 +0800 From: Kent Gibson To: Andy Shevchenko Cc: Linus Walleij , Bartosz Golaszewski , Yury Norov , linux-gpio@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Shubhrajyoti Datta , Srinivas Neeli , Michal Simek , Bartosz Golaszewski , Rasmus Villemoes , Marek =?iso-8859-1?Q?Beh=FAn?= Subject: Re: [PATCH v1 5/5] gpiolib: cdev: Utilize more bitmap APIs Message-ID: References: <20230926052007.3917389-1-andriy.shevchenko@linux.intel.com> <20230926052007.3917389-6-andriy.shevchenko@linux.intel.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231002_024249_695072_5E6A7109 X-CRM114-Status: GOOD ( 29.67 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Oct 02, 2023 at 12:32:22PM +0300, Andy Shevchenko wrote: > On Mon, Oct 02, 2023 at 05:25:05PM +0800, Kent Gibson wrote: > > On Mon, Oct 02, 2023 at 12:05:11PM +0300, Andy Shevchenko wrote: > > > On Wed, Sep 27, 2023 at 10:23:12PM +0800, Kent Gibson wrote: > > > > On Wed, Sep 27, 2023 at 04:59:34PM +0300, Andy Shevchenko wrote: > > > > > On Wed, Sep 27, 2023 at 09:49:35PM +0800, Kent Gibson wrote: > > > > > > On Wed, Sep 27, 2023 at 03:17:06PM +0300, Andy Shevchenko wrote: > > > > > > > On Wed, Sep 27, 2023 at 09:32:11AM +0800, Kent Gibson wrote: > > ... > > > > > > > > Yet, it opens a way to scale this in case we might have v3 ABI that let's say > > > > > > > allows to work with 512 GPIOs at a time. With your code it will be much harder > > > > > > > to achieve and see what you wrote about maintenance (in that case). > > > > > > > > > > > > v3 ABI?? libgpiod v2 is barely out the door! > > > > > > Do you have any cases where 64 lines per request is limiting? > > > > > > > > > > IIRC it was SO question where the OP asks exactly about breaking the 64 lines > > > > > limitation in the current ABI. > > > > > > > > > > > If that sort of speculation isn't premature optimisation then I don't know > > > > > > what is. > > > > > > > > > > No, based on the real question / discussion, just have no link at hand. > > > > > But it's quite a niche, I can agree. > > > > > > > > Let me know if you find a ref to that discussion - I'm curious. > > > > > > Here it is (read comments as well): > > > https://stackoverflow.com/questions/76307370/control-gpio-from-linux-userspace-with-linux-gpio-h > > > > > > > That question looks to me to be confusing how many GPIOs can be > > requested per request (64) and in total (effectively unlimited) - thinking > > they are the same. > > That could be due to their desire to use the gpiod_chip_get_all_lines() > > convenience function with a chip with more than 64 lines, rather than > > because they have an actual need for the lines to be managed in a single > > request. > > > > So that doesn't look like a genuine use case to me - just a "what if I > > want to do X" question. Certainly not something that would warrant a v3 > > ABI. > > Sure, and I'm not talking about v3 ABI to go for, see the word "might" in my > reply in the first paragraph of this message. > Ok, so your original point was pure speculation. Cheers, Kent. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel