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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 A3808ECDE47 for ; Thu, 8 Nov 2018 16:54:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7706520827 for ; Thu, 8 Nov 2018 16:54:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7706520827 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arndb.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727251AbeKICbG (ORCPT ); Thu, 8 Nov 2018 21:31:06 -0500 Received: from mail-qk1-f193.google.com ([209.85.222.193]:35143 "EHLO mail-qk1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726788AbeKICbF (ORCPT ); Thu, 8 Nov 2018 21:31:05 -0500 Received: by mail-qk1-f193.google.com with SMTP id w204so2663829qka.2; Thu, 08 Nov 2018 08:54:43 -0800 (PST) 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=/r2pkmkSdytf8ArSse1xG1oINIbNgF2IBwly2XdtLSM=; b=CKkq+Bnha5GPO/pHs2OKdTcHWMs9qLQaWCmDjhLDU68Ho+11QB1H+B3f0pMBog2R2C rLojGQxtuOAckTAlEKuBsCKgUyoXGSQ75e6TMblZUSQN9X1Y322RTDvYe8gtIYVHE+/6 9a4qYaIXZ7OHCQhdMYNfbJWVtFxj6DQTL2txtVaJIyTIy2pWEC3dNGNt9m5B/nUFU5OH 5u67HSP96gsZB/OR6QNUP17N9z72G7MLXPhkW+dooOpULD5TB+p7gfEniFQlBNpfyWkW fmGgkL/zW2fSH+QvpksIcn/c52g4inajo+J0hQxOmDjgPVrz81ebVCVxMNKQVV7We/0M dwGw== X-Gm-Message-State: AGRZ1gL15lE5pZfW/hHgtf9+5drA5q3pfDlGlazgPmChvfy4nO5V6vx/ nkyXjYRlJvmyxijoUazbEn7TpCU2r9u0s/8AjB8= X-Google-Smtp-Source: AJdET5f0+LsipQZIjl1jQJwxMKKfg4heXFulrsmEoYn1bKbocwZOfSlModat2pgUr/beDw/cGDipi4q8OLEd5TsPGP8= X-Received: by 2002:a0c:d992:: with SMTP id y18mr5322062qvj.161.1541696083229; Thu, 08 Nov 2018 08:54:43 -0800 (PST) MIME-Version: 1.0 References: <20181104155501.14767-1-TheSven73@googlemail.com> <20181104155501.14767-5-TheSven73@googlemail.com> In-Reply-To: From: Arnd Bergmann Date: Thu, 8 Nov 2018 17:54:10 +0100 Message-ID: Subject: Re: [PATCH anybus v3 4/6] bus: support HMS Anybus-S bus To: thesven73@gmail.com Cc: svendev@arcx.com, Rob Herring , Linus Walleij , Lee Jones , Mark Rutland , =?UTF-8?Q?Andreas_F=C3=A4rber?= , Thierry Reding , David Lechner , noralf@tronnes.org, Johan Hovold , Michal Simek , michal.vokac@ysoft.com, gregkh , John Garry , Geert Uytterhoeven , Robin Murphy , Paul Gortmaker , Sebastien Bourdelin , Icenowy Zheng , Stuart Yoder , Maxime Ripard , Linux Kernel Mailing List , DTML Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 8, 2018 at 4:47 PM Sven Van Asbroeck wrote: > On Thu, Nov 8, 2018 at 9:07 AM Arnd Bergmann wrote: > > I see this is called from the interrupt handler at the moment, which > > means you cannot call sleeping functions, but it also means that > > the timeout may never happen because the timer tick IRQ cannot > > get through. That means you may have to change the irq handler > > logic, e.g. to try this a few times but then defer to a bottom half > > if it fails for a long time. > > Touche ! Yes, this is very likely a big problem. > > What if I converted the interrupt handler into a threaded interrupt handler? > That would allow the timer tick to get through, correct? Yes, with a threaded IRQ handler, the tick comes through, and you can use a sleeping function to back off between the retries. Arnd