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,DKIMWL_WL_HIGH, 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 11E95C2BBCF for ; Fri, 18 Dec 2020 02:52:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C6F6723A52 for ; Fri, 18 Dec 2020 02:52:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731514AbgLRCwg (ORCPT ); Thu, 17 Dec 2020 21:52:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37944 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727079AbgLRCwf (ORCPT ); Thu, 17 Dec 2020 21:52:35 -0500 Received: from mail-pf1-x42b.google.com (mail-pf1-x42b.google.com [IPv6:2607:f8b0:4864:20::42b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A5441C0617B0 for ; Thu, 17 Dec 2020 18:51:55 -0800 (PST) Received: by mail-pf1-x42b.google.com with SMTP id w6so662391pfu.1 for ; Thu, 17 Dec 2020 18:51:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=mime-version:content-transfer-encoding:in-reply-to:references :subject:from:cc:to:date:message-id:user-agent; bh=ul+JQXSNam3Jh6+49O94MwvKAzXGAJzUccEcBcdHWAs=; b=G42IndBReRqVZg+a2MKBCb1Kt4lvbF/WksJWYeKee00AmCVPkhoe12N+igTMnPs45K MuUMt7Et/HKLyEo+4sPBXph5sJD74t1/+Iw+f6zebD11w1O6iabrgvphBzxkxe4kyFef nc9nRW4sg0ffad3/Ol1YKAhOt2Ycpb8gAek78= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:content-transfer-encoding :in-reply-to:references:subject:from:cc:to:date:message-id :user-agent; bh=ul+JQXSNam3Jh6+49O94MwvKAzXGAJzUccEcBcdHWAs=; b=pwL1ebaYyTqKUB+/5dgYHM2astmy0J3tkXDi11GrKSXaEU5xZiaoWJFii+VCCuU0jM douXYWEOxiFsOt9NYqAR8bTjrIY5/W9xhoYvVO8zEk2Ut2vZXW9wrY2GcvidTktOmwTz bu2eZKbev6C6SBLNpAXnxzYW0kp8JMKdOcVokTrAa7SvO5TZLshbGwBkLxjoJZ5HBj6D dYgWnebVFexVMqM28G6KQ7tmabI4sdzWXI6ozPZtZnSlFcR4xfHryzKkNgy1ZDuSf5hM iCcSZzKH4MKW+i/Mh/LI5G8aA7S5X1Xs0QJyy90dNPMvzMpn+K5UyA9SluMnpfKwsfHv tk4A== X-Gm-Message-State: AOAM533Hpc1tNnwUhqPaaDa+Kk0rPtCDCZqW/9DnfYr4AoO/zsGON/I4 osHvF2SdXx/CfL0ChTO1F+fxPA== X-Google-Smtp-Source: ABdhPJwg5+G+1UyV/hGw2/rBQu+naxSAN5HNPZscRDaWeHpeyp1drWCU5fDXVg/R//PgykEOZubs6g== X-Received: by 2002:a62:1617:0:b029:1a3:c265:a50c with SMTP id 23-20020a6216170000b02901a3c265a50cmr2150152pfw.77.1608259915209; Thu, 17 Dec 2020 18:51:55 -0800 (PST) Received: from chromium.org ([2620:15c:202:201:3e52:82ff:fe6c:83ab]) by smtp.gmail.com with ESMTPSA id u9sm6943347pfl.143.2020.12.17.18.51.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Dec 2020 18:51:54 -0800 (PST) Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable In-Reply-To: References: <20201216144114.v2.1.I99ee04f0cb823415df59bd4f550d6ff5756e43d6@changeid> <20201216144114.v2.3.I07afdedcc49655c5d26880f8df9170aac5792378@changeid> <160817939232.1580929.12113046418592056259@swboyd.mtv.corp.google.com> Subject: Re: [PATCH v2 3/4] spi: spi-geni-qcom: Don't try to set CS if an xfer is pending From: Stephen Boyd Cc: Mark Brown , msavaliy@qti.qualcomm.com, Akash Asthana , Roja Rani Yarubandi , Andy Gross , Bjorn Andersson , linux-arm-msm , LKML , linux-spi To: Doug Anderson Date: Thu, 17 Dec 2020 18:51:52 -0800 Message-ID: <160825991289.1580929.8225600641746583053@swboyd.mtv.corp.google.com> User-Agent: alot/0.9.1 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Quoting Doug Anderson (2020-12-17 13:35:08) >=20 > If we wanted to truly make this driver super robust against ridiculous > interrupt latencies then, presumably, we could handle the SPI timeout > ourselves but before timing out we could check to see if the > interrupts were pending. Then we could disable our interrupts, > synchronize our interrupt handler, handle the interrupt directly, and > then re-enable interrupts. If we did this then transfers could > continue to eek their way through even if interrupts were completely > blocked. IMO, it's not worth it. I'm satisfied with not crashing and > not getting the state machine too out-of-whack. >=20 Ok that's fair. If it's not worth the effort then let's drop this idea.