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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 214C0C28D13 for ; Thu, 25 Aug 2022 14:46:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233563AbiHYOqs (ORCPT ); Thu, 25 Aug 2022 10:46:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56540 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241414AbiHYOqr (ORCPT ); Thu, 25 Aug 2022 10:46:47 -0400 Received: from mo4-p01-ob.smtp.rzone.de (mo4-p01-ob.smtp.rzone.de [85.215.255.54]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 83D1BB274B; Thu, 25 Aug 2022 07:46:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; t=1661438748; s=strato-dkim-0002; d=xenosoft.de; h=In-Reply-To:From:References:Cc:To:Subject:Date:Message-ID:Cc:Date: From:Subject:Sender; bh=TGjpNc9Iuyfn98dr3RH7hoDzKwuTCfRh4C04vBts5Fg=; b=dtZq+0iKVkD6TINHagtmuY0Xt7XGDXBcC07Ws3w6KwMSuhBIch7u07xyjVOPrzftki bEGma4xfVi3495mJITB6dNpH8hsS2ThJC2+seu3ewKmEVSoNV/0sNl2EJnRO4oP+jVlL 4zvpYjjfSO/J4+H2tjmWYaS2SfwLM13hDoAnABwGOklfxPH8H+1vWcgN0eznKvFY0c2W 2hNQjuvaSPBEEyZ2dV5ACpSKIM+Vc95E46lkInsu5i9tI8oEW5xb+nYzCzHMiwY+4I6T R3rz9zUWwryNRdg67isdNzS7/uA0J1w85EN6QrDVOjan1+5vESxMwsHzHHNpp/AlK7kS pEkA== Authentication-Results: strato.com; dkim=none X-RZG-AUTH: ":L2QefEenb+UdBJSdRCXu93KJ1bmSGnhMdmOod1DhGM4l4Hio94KKxRySfLxnHfJ+Dkjp5DdBfio0Gngadwjc4Jbqft7lQCs4naYEQyjFZmg7Rw==" X-RZG-CLASS-ID: mo00 Received: from [IPV6:2a02:8109:8980:4474:9977:7bf7:b1d0:60a2] by smtp.strato.de (RZmta 47.47.0 AUTH) with ESMTPSA id f01469y7PEjjWeZ (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits)) (Client did not present a certificate); Thu, 25 Aug 2022 16:45:45 +0200 (CEST) Message-ID: Date: Thu, 25 Aug 2022 16:45:45 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.2.0 Subject: Re: [PATCH] i2c: pasemi: Add IRQ support for Apple Silicon To: Michael Ellerman , Arminder Singh , linux-kernel@vger.kernel.org Cc: Sven Peter , Alyssa Rosenzweig , Hector Martin , Benjamin Herrenschmidt , Paul Mackerras , linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-i2c@vger.kernel.org, Darren Stevens , "R.T.Dickinson" , Christian Zigotzky References: <87h723lodh.fsf@mpe.ellerman.id.au> From: Christian Zigotzky In-Reply-To: <87h723lodh.fsf@mpe.ellerman.id.au> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org On 23 August 2022 at 03:50 am, Michael Ellerman wrote: > Arminder Singh writes: >> This is the first time I'm interacting with the Linux mailing lists, so >> please don't eviscerate me *too much* if I get the formatting wrong. >> Of course I'm always willing to take criticism and improve my formatting >> in the future. >> >> This patch adds support for IRQs to the PASemi I2C controller driver. >> This will allow for faster performing I2C transactions on Apple Silicon >> hardware, as previously, the driver was forced to poll the SMSTA register >> for a set amount of time. >> >> With this patchset the driver on Apple silicon hardware will instead wait >> for an interrupt which will signal the completion of the I2C transaction. >> The timeout value for this completion will be the same as the current >> amount of time the I2C driver polls for. >> >> This will result in some performance improvement since the driver will be >> waiting for less time than it does right now on Apple Silicon hardware. >> >> The patch right now will only enable IRQs for Apple Silicon I2C chips, >> and only if it's able to successfully request the IRQ from the kernel. >> >> === Testing === >> >> This patch has been tested on both the mainline Linux kernel tree and >> the Asahi branch (https://github.com/AsahiLinux/linux.git) on both an >> M1 and M2 MacBook Air, and it compiles successfully as both a module and >> built-in to the kernel itself. The patch in both trees successfully boots >> to userspace without any hitch. >> >> I do not have PASemi hardware on hand unfortunately, so I'm unable to test >> the impact of this patch on old PASemi hardware. This is also why I've >> elected to do the IRQ request and enablement on the Apple platform driver >> and not in the common file, as I'm not sure if PASemi hardware supports >> IRQs. > I've added Darren and Christian to Cc, they have helped with PASemi > development and testing in the past, and may be able to help test this > series on PASemi hardware. > > cheers Tested-by: Christian Zigotzky on an A-EON AmigaOne X1000 with a PASemi PWRficient PA6T-1682 processor.