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=-11.3 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL 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 81312C433E0 for ; Thu, 28 May 2020 16:10:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5E1E82071A for ; Thu, 28 May 2020 16:10:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="cp8r+1sL" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404896AbgE1QKF (ORCPT ); Thu, 28 May 2020 12:10:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57844 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404887AbgE1QKD (ORCPT ); Thu, 28 May 2020 12:10:03 -0400 Received: from mail-oo1-xc41.google.com (mail-oo1-xc41.google.com [IPv6:2607:f8b0:4864:20::c41]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4E27EC08C5C6 for ; Thu, 28 May 2020 09:10:03 -0700 (PDT) Received: by mail-oo1-xc41.google.com with SMTP id 18so1093651ooy.3 for ; Thu, 28 May 2020 09:10:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=COfs6qCE8hM8QVaiAzFL6DNp7cNTDmfQQIXgkIZMl/w=; b=cp8r+1sLeeFw8G0IzpIBNAfkrRVlgDBX2s0RLF2xI1OSGCJKWiQnp5W2nkCWJPd1vp tCQP9fdSOpZq8tUcVtUsQmQVV9MkuVaMgqp4Ci1CGREDLP/dqAinYjBm593K/Zl947BY +jOFNTDrgTswwCWMatNlxUUstKyjbQ9EqeGj8lx51OG+TGFnq6XGMMHkiucOefLBXmAb 4b4brcQH3609QeZt/cMS0fz78HqHetKNWWbOZOoj2SCgg5PbRM14FPNCSLiAQNQeMc5H EoxbVg1ikVFWdbN8FcxHgySncNXAFIo4EZ2taMW23olSkXzp/bKBwpOu0GNgllIV6DeZ QqGQ== 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=COfs6qCE8hM8QVaiAzFL6DNp7cNTDmfQQIXgkIZMl/w=; b=rqDKMz1k0APE6KULyveAKEpJja7uUUEo8P8ohWoOdY++b8DrZm40ww9t6ROtNxwfmJ pqI3+XSaHGKLr65197t4IxsSyuwhyvFZMXbWc2mDlFn+VHJ/bPLHuwHsiqH2xMHonap3 zAbmUDlLDNZ2wrRlEpEy6esATfYeERFhA3oEHicYqZD9swPnFlJOtzQfMR9eEjgHTA/K fOgLQUQ5pYjPujSlO9sRtAD1+6bZYCIBqFOhT6YhOVpvrFPERmf7oxFHtgxfP2UR6Gp6 uSR7HWTf16wywgk21KE2Tks5m+ccRM30RfKysPSpdD5Cyu+XngtFVEXPNGMc95KdYm3a FSWA== X-Gm-Message-State: AOAM5317YQe652UUoXVADF6A7jLvjYuFQxQA8P5gVN7DAjPKCxExRGRV uLlfhYjOszAJi/eSBr9+SJYm7oiDKFbSgGCSOfvTpQ== X-Google-Smtp-Source: ABdhPJzw0SA7Pqgbo/xntKafhIdeFTSXoamjxO2GxCLPaaFW1LFuSDsjxSYmXaw/kRoCf6Eck45wNbm5HRyvM06nHTI= X-Received: by 2002:a4a:9624:: with SMTP id q33mr3091583ooi.53.1590682197632; Thu, 28 May 2020 09:09:57 -0700 (PDT) MIME-Version: 1.0 References: <6144404cb26d1f797fd7e87b124bcaf8@walle.cc> <20200526220928.49939-1-saravanak@google.com> In-Reply-To: From: Saravana Kannan Date: Thu, 28 May 2020 09:09:21 -0700 Message-ID: Subject: Re: [PATCH v3] driver core: Update device link status correctly for SYNC_STATE_ONLY links To: "Rafael J. Wysocki" Cc: Greg Kroah-Hartman , Michael Walle , "Cc: Android Kernel" , "Rafael J. Wysocki" , Linux Kernel Mailing List 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 Wed, May 27, 2020 at 1:26 AM Rafael J. Wysocki wrote: > > On Wed, May 27, 2020 at 12:09 AM Saravana Kannan wrote: > > > > When SYNC_STATE_ONLY support was added in commit 05ef983e0d65 ("driver > > core: Add device link support for SYNC_STATE_ONLY flag"), > > SYNC_STATE_ONLY links were treated similar to STATELESS links in terms > > of not blocking consumer probe if the supplier hasn't probed yet. > > > > That caused a SYNC_STATE_ONLY device link's status to not get updated. > > Since SYNC_STATE_ONLY device link is no longer useful once the > > consumer probes, commit 21c27f06587d ("driver core: Fix > > SYNC_STATE_ONLY device link implementation") addresses the status > > update issue by deleting the SYNC_STATE_ONLY device link instead of > > complicating the status update code. > > > > However, there are still some cases where we need to update the status > > of a SYNC_STATE_ONLY device link. This is because a SYNC_STATE_ONLY > > device link can later get converted into a normal MANAGED device link > > when a normal MANAGED device link is created between a supplier and > > consumer that already have a SYNC_STATE_ONLY device link between them. > > > > If a SYNC_STATE_ONLY device link's status isn't maintained correctly > > till it's converted to a normal MANAGED device link, then the normal > > MANAGED device link will end up with a wrong link status. This can cause > > a warning stack trace[1] when the consumer device probes successfully. > > > > This commit fixes the SYNC_STATE_ONLY device link status update issue > > where it wouldn't transition correctly from DL_STATE_DORMANT or > > DL_STATE_AVAILABLE to DL_STATE_CONSUMER_PROBE. It also resets the status > > back to DL_STATE_DORMANT or DL_STATE_AVAILABLE if the consumer probe > > fails. > > > > [1] - https://lore.kernel.org/lkml/20200522204120.3b3c9ed6@apollo/ > > Fixes: 05ef983e0d65 ("driver core: Add device link support for SYNC_STATE_ONLY flag") > > Fixes: 21c27f06587d ("driver core: Fix SYNC_STATE_ONLY device link implementation") > > Reported-by: Michael Walle > > Tested-by: Michael Walle > > Signed-off-by: Saravana Kannan > > Reviewed-by: Rafael J. Wysocki > Thanks Rafael for the review. And thanks again Michael for all the logs! -Saravana