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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_2 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 4589FC54FCC for ; Tue, 21 Apr 2020 06:53:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 24BB420679 for ; Tue, 21 Apr 2020 06:53:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kemnade.info header.i=@kemnade.info header.b="E5nwg9HR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726626AbgDUGxp (ORCPT ); Tue, 21 Apr 2020 02:53:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34614 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1725926AbgDUGxo (ORCPT ); Tue, 21 Apr 2020 02:53:44 -0400 Received: from mail.andi.de1.cc (mail.andi.de1.cc [IPv6:2a01:238:4321:8900:456f:ecd6:43e:202c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3C826C061A0F; Mon, 20 Apr 2020 23:53:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=kemnade.info; s=20180802; h=Content-Transfer-Encoding:Content-Type: MIME-Version:References:In-Reply-To:Message-ID:Subject:Cc:To:From:Date:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=fR1NqAKRcDcvju0ewc8DInHgEpyMK6T3//JWLHgIwrs=; b=E5nwg9HRQ3wDFu/t/mct+wWJRS iBQv0E1ZY9dliaFMIvhkeU8OQkTnw+6p49qika7cyI5o/LXwjGbXxmXEjGO5m6nCDenrw8cpjxcOq juKAyLj4nLjF2Jn8ngSNcZJ9umIRFTN0cK4tbYAkUKNd+n4FCMWODNQDiFrp/btU76oI=; Received: from p200300ccff1389001a3da2fffebfd33a.dip0.t-ipconnect.de ([2003:cc:ff13:8900:1a3d:a2ff:febf:d33a] helo=aktux) by mail.andi.de1.cc with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1jQmmn-0005R2-Jg; Tue, 21 Apr 2020 08:53:38 +0200 Date: Tue, 21 Apr 2020 08:53:36 +0200 From: Andreas Kemnade To: "H. Nikolaus Schaller" Cc: Tony Lindgren , Evgeniy Polyakov , Greg Kroah-Hartman , Linux Kernel Mailing List , linux-omap , Adam Ford , "Andrew F . Davis" , Vignesh R Subject: Re: [PATCHv3] w1: omap-hdq: Simplify driver with PM runtime autosuspend Message-ID: <20200421085336.32cf8ffe@aktux> In-Reply-To: References: <20191217004048.46298-1-tony@atomide.com> <7B8C7DD9-095B-48FC-9642-695D07B79E97@goldelico.com> <20200416184638.GI37466@atomide.com> <3197C3F0-DEB9-4221-AFBD-4F2A08C84C4C@goldelico.com> <20200417164340.3d9043d1@aktux> <6430AF54-849E-456B-8DB0-B4478BBDB78D@goldelico.com> <20200417150721.GL37466@atomide.com> <8E062482-5D5D-4837-9980-D6C708DD24D4@goldelico.com> <20200420150802.GR37466@atomide.com> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 20 Apr 2020 23:11:18 +0200 "H. Nikolaus Schaller" wrote: > Hi Tony, > > > Am 20.04.2020 um 17:08 schrieb Tony Lindgren : > > > > * H. Nikolaus Schaller [200417 21:04]: > >> To me it looks as if reading hqd too quickly after omap_hdq_runtime_resume() > >> may be part of the problem, although it is 0.4 seconds between [ 18.355163] > >> and [ 18.745269]. So I am not sure about my interpretation. > >> > >> A different attempt for interpretation may be that trying to read the > >> slave triggers omap_hdq_runtime_resume() just before doing the > >> first hdq_read_byte(). > > > > Hmm so I wonder if adding msleep(100) at the end of > > omap_hdq_runtime_resume() might help? > > I have tried and initially it did boot and work once. > But after the second boot/reboot the effect was back. > > This is something I have observed previously, that the issue > is there in ca. 9 or 10 boot attempts. So I would assume > some race condition with udev reading the uevent file of the > bq27xxx bus client and hence through hdq. > > I already had noticed some hqd_read activity right after probing > success. > > I had also tried to change pm_runtime_set_autosuspend_delay(, 1000) > with no success. And I tried to call omap_hdq_runtime_resume() at the > end of probe. > > The only maybe important observation was when I disabled all > kernel modules except *hdq*.ko and *bq27*.ko. Then I did only > get an emergency shell so that it is quite similar to the > scenario Andreas has tested. With this setup it did work. > So I guess without idling uarts? > I then tried to reenable other kernel modules but the result > wasn't convincing that it gives a reliable result. > > So I have still no clear indication when the problem occurs and > when not. > Hmm, last summer I had problems even without that patch reading temperature while doing umts transfers. Maybe there are some connections, maybe not. For that scenario we might have emc issues, thermal problems or a real kernel problem. Regards, Andreas