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=-0.8 required=3.0 tests=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 41774C28CBC for ; Wed, 6 May 2020 14:20:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1BBBF206D5 for ; Wed, 6 May 2020 14:20:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728769AbgEFOU7 (ORCPT ); Wed, 6 May 2020 10:20:59 -0400 Received: from mout.kundenserver.de ([212.227.126.130]:43649 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726114AbgEFOU6 (ORCPT ); Wed, 6 May 2020 10:20:58 -0400 Received: from mail-qk1-f173.google.com ([209.85.222.173]) by mrelayeu.kundenserver.de (mreue010 [212.227.15.129]) with ESMTPSA (Nemesis) id 1N7zW7-1j16Z13mx1-014z6D; Wed, 06 May 2020 16:20:57 +0200 Received: by mail-qk1-f173.google.com with SMTP id f13so2080270qkh.2; Wed, 06 May 2020 07:20:56 -0700 (PDT) X-Gm-Message-State: AGi0PuaFK71bYSa1gufG+QjdDPiYfBlm7+S53VcCoaPvswI424tQPZcp tLVf91fdjNA/5e9Bs8ecmz5tCNsiB8TnP17ZcgQ= X-Google-Smtp-Source: APiQypKgaluquciflnBcztR1WN9teptLeSIWzng6zhGKuokJY8nJLdN0sgdbAFnBGd3XVoUkDA88FSzspEE+6sGwvLc= X-Received: by 2002:a05:620a:3c5:: with SMTP id r5mr9076074qkm.138.1588774855617; Wed, 06 May 2020 07:20:55 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Arnd Bergmann Date: Wed, 6 May 2020 16:20:39 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 1/2] alpha: add a delay between RTC port write and read To: Mikulas Patocka Cc: Richard Henderson , Ivan Kokshaysky , Matt Turner , Greg Kroah-Hartman , alpha , Sinan Kaya , linux-serial@vger.kernel.org, linux-rtc@vger.kernel.org Content-Type: text/plain; charset="UTF-8" X-Provags-ID: V03:K1:ODdZcuhx4O1OqlUVtvGTL+/T4HDL0HaWhlYX8QrlhAYTuPqcQen v3tE9VT698mp45ej1a5pC3uCKyhUPUrEqEiAsRXAd8kJdsiOI10q9KyrlRF3kbYKrZPlpOP /42VbPsVBD/3V0QcThzLG9y+uhHft/Yqiw2en80oIt5Bze5++4xIgNMAaKsqGBKeP1rfWnM KhBWlB1d67oBCY14BfGhQ== X-UI-Out-Filterresults: notjunk:1;V03:K0:BQMkoMeXna0=:+EkJRWs27VHfOCbmAdw+uW 7EieW0z9uPcLy1V+z4cGJwACUycFb0iuEgfBSIa7H36SYKmDc6NSQb44ZvqbfDkd7oQEyUioW dSMVNmRVEJJ2hObCv/0UR5rDcZbQXsNqx8N+jcZUF9cQ9ODr0+Z144X9i32T+F7OR7KKWMNk7 0zQNsYrzUQBe8RrfOTyQHxY++KvXo9ysSgUzhkCh3JBmPXmuDVAFVVI2htA25sgNBpDMLmPKp esrRq9A8dju6TAYxBESZQVyF5VUlFPWpVo2xTW06EI8UlzUv49LdFPW3aDxpygjWWNTtwNd/R QYAY1AbO3sNHOpB/2U44sw5/+DwexzgRh/dwmywdvU6p1+HrGKDikY34cCFJ6yhCsdH9nJGFy cOi+xmj59CeJkofreqn1DfVHCdnTQr5twI3gmgmdVhDBFqyaJF+UTiZxPaE0TL3YUhapQJhos 6RC1I7/zG8m85kza48cu84XZKUU/Y03XNok7cIE0g24K5/XsWKnObiF+axxRhdsrlOiT9rZEx 9UdAqC0XGKnEQmYLfhZLpR7+K/3ovS+5l7/E4fKfHgojhug3ksY+gBHSSp9qrwcCt7enJwdqb gqbO+5AoDhtrJVfrektjAnAG2T64i9F1trO3ROwFRsRNx2bdWfwMqybTTRF9hiC2ZmcUkrVDu zqfWB/9dmd56HlJeKRM4iCs8sEOPYfurqyYNzQIzXhPF98TKXcAA8HiTrtMh+yS7rA1OfL+/X KJ7AqYPvkIcYio5RlF5vp6H2p1mF8cL5P0ZIVXTv5xj/84VgtUNpM54zWK9L06kex40C7OPIO lgKvviJ4Sndf+AFoVRUMH4jFWf5Nifx4W9e0zgFxfnJe62XyzI= Sender: linux-rtc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rtc@vger.kernel.org On Wed, May 6, 2020 at 1:21 PM Mikulas Patocka wrote: > /* > * The yet supported machines all access the RTC index register via > * an ISA port access but the way to access the date register differs ... > + * > + * The ISA bus on Alpha Avanti doesn't like back-to-back accesses, > + * we need to add a small delay. > */ > #define CMOS_READ(addr) ({ \ > outb_p((addr),RTC_PORT(0)); \ > +udelay(2); \ > inb_p(RTC_PORT(1)); \ The inb_p() / outb_p() functions are meant to already have a delay in them, maybe we should just add it there for alpha? Arnd